improvement and fixes for bindings test (DO NOT MERGE)

* the name "testComplete" will cause test runner to actually execute it as a
  test case, which is not the intention here, changed to "notifyComplete"
* the test depends on "/sdcard/bindings_test.html". since the same file is
  already being carried in the apk as asset, added a setup/teardown step to
  extract the file. this removes manual setup step for the tests.

Change-Id: I74dc42a7ca0442a84910441e535d950c049efc98
3 files changed