fix pa sha (#445)

* Add check for pa sha passed in via yaml + docker

* Update cmake execute command to change working dir

* Remove changes to top level Cmakelists files

src/c++/perf_analyzer/CMakeLists.txt

@@ -35,11 +35,10 @@ add_subdirectory(client_backend)
 
 find_package(Git REQUIRED)
 
-execute_process(COMMAND
-  "${GIT_EXECUTABLE}" log -n 1 --abbrev-commit --format=format:%h
+execute_process(WORKING_DIRECTORY ${CMAKE_SOURCE_DIR}
+  COMMAND "${GIT_EXECUTABLE}" log -n 1 --abbrev-commit --format=format:%h
   RESULT_VARIABLE RETURN_CODE
   OUTPUT_VARIABLE GIT_SHA)
-
 if(NOT RETURN_CODE EQUAL "0")
   set(GIT_SHA "unknown")
 endif()