Fix yml syntax (#5274)

diff --git a/build_tools/buildkite/cmake/android/arm64-v8a/pipeline.yml b/build_tools/buildkite/cmake/android/arm64-v8a/pipeline.yml
index bc1e71c..d9797d2 100644
--- a/build_tools/buildkite/cmake/android/arm64-v8a/pipeline.yml
+++ b/build_tools/buildkite/cmake/android/arm64-v8a/pipeline.yml
@@ -61,7 +61,7 @@
       - "cd build-android/"
       # vulkan tests using khr_shader_float16_int8 are failing on pixel4.
       # Disabling it until we identify the root cause.
-      - "ctest --output-on-failure --label-exclude \"^vulkan_uses_vk_khr_shader_float16_int8$\""
+      - "ctest --output-on-failure --label-exclude \"^vulkan_uses_vk_khr_shader_float16_int8\\$\""
     agents:
       - "android-soc=snapdragon-855"
       - "queue=test-android"