Merge "Read LLVM version from $LLVM_PREBUILTS_VERSION if set."

ANDROID_BUILD_TOP = os.environ.get("ANDROID_BUILD_TOP", ".")

LLVM_PREBUILTS_VERSION = os.environ.get("LLVM_PREBUILTS_VERSION")

def get_clang_prebuilts_version(global_go):

  if LLVM_PREBUILTS_VERSION:

    return LLVM_PREBUILTS_VERSION

  # TODO(b/187231324): Get clang version from the json file once it is no longer

  # hard-coded in global.go

  if global_go is None: