Add a new error code for App Indexing Plugin

Add a new error code and the corresponding message.
and adjust one error code handling logic.

Test: NA
Change-Id: If98463bf57c9762ef457f538a7824144e88f7a82
(cherry picked from commit 623c02e1530771bc1f2ec8214393be792c86151d)
3 files changed
tree: 6eeccffe0bdc1183c48c8edee5e9f7af84f513aa
  1. BUILD
  2. google-appindexing.iml
  3. lib/
  4. resources/
  5. src/
  6. testData/
  7. testSrc/