Delete unnecessary Kokoro shell scripts

tools/internal_ci/linux/sanitizer/pull_request/grpc_c_asan.sh

-#!/bin/bash
-# Copyright 2017 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -ex
-
-# change to grpc repo root
-cd $(dirname $0)/../../../../..
-
-source tools/internal_ci/helper_scripts/prepare_build_linux_rc
-
-tools/run_tests/run_tests_matrix.py -f c asan --inner_jobs 16 -j 1 --internal_ci --filter_pr_tests --base_branch origin/master --max_time=3600

tools/internal_ci/linux/sanitizer/pull_request/grpc_c_msan.sh

-#!/bin/bash
-# Copyright 2017 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -ex
-
-# change to grpc repo root
-cd $(dirname $0)/../../../../..
-
-source tools/internal_ci/helper_scripts/prepare_build_linux_rc
-
-tools/run_tests/run_tests_matrix.py -f c msan --inner_jobs 16 -j 1 --internal_ci --filter_pr_tests --base_branch origin/master --max_time=3600

tools/internal_ci/linux/sanitizer/pull_request/grpc_c_tsan.sh

-#!/bin/bash
-# Copyright 2017 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -ex
-
-# change to grpc repo root
-cd $(dirname $0)/../../../../..
-
-source tools/internal_ci/helper_scripts/prepare_build_linux_rc
-
-tools/run_tests/run_tests_matrix.py -f c tsan --inner_jobs 16 -j 1 --internal_ci --filter_pr_tests --base_branch origin/master --max_time=3600

tools/internal_ci/linux/sanitizer/pull_request/grpc_c_ubsan.sh

-#!/bin/bash
-# Copyright 2017 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -ex
-
-# change to grpc repo root
-cd $(dirname $0)/../../../../..
-
-source tools/internal_ci/helper_scripts/prepare_build_linux_rc
-
-tools/run_tests/run_tests_matrix.py -f c ubsan --inner_jobs 16 -j 1 --internal_ci --filter_pr_tests --base_branch origin/master --max_time=3600

tools/internal_ci/linux/sanitizer/pull_request/grpc_cpp_asan.sh

-#!/bin/bash
-# Copyright 2017 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -ex
-
-# change to grpc repo root
-cd $(dirname $0)/../../../../..
-
-source tools/internal_ci/helper_scripts/prepare_build_linux_rc
-
-tools/run_tests/run_tests_matrix.py -f c++ asan --inner_jobs 16 -j 1 --internal_ci --filter_pr_tests --base_branch origin/master --max_time=3600

tools/internal_ci/linux/sanitizer/pull_request/grpc_cpp_tsan.sh

-#!/bin/bash
-# Copyright 2017 gRPC authors.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-set -ex
-
-# change to grpc repo root
-cd $(dirname $0)/../../../../..
-
-source tools/internal_ci/helper_scripts/prepare_build_linux_rc
-
-tools/run_tests/run_tests_matrix.py -f c++ tsan --inner_jobs 16 -j 1 --internal_ci --filter_pr_tests --base_branch origin/master --max_time=3600