avoid error if bazel intermediates dir already exists

Previously, the build failed if the directory already existed,
so mixed builds had to be null builds.

Test: lunch aosp_flame && USE_BAZEL=1 USE_BAZEL_ANAYSIS=1 m libc &&
  USE_BAZEL=1 USE_ANALYSIS=1 m libc
Change-Id: I167cb82b3e47e9388a1ebca7daffe45f91474125

android/bazel_handler.go

@@ -371,7 +371,11 @@ func (context *bazelContext) InvokeBazel() error {
 	var cqueryOutput string
 	var err error
 
-	err = os.Mkdir(absolutePath(context.intermediatesDir()), 0777)
+	intermediatesDirPath := absolutePath(context.intermediatesDir())
+	if _, err := os.Stat(intermediatesDirPath); os.IsNotExist(err) {
+		err = os.Mkdir(intermediatesDirPath, 0777)
+	}
+
 	if err != nil {
 		return err
 	}