Fix crash when altering rate for voicemails without content.

- Repro for crash was to click on voicemail from call log without
  content, try to play it (which would silently fail), then try to
  use the rate increase/decrease buttons.
- The error being reported to the ui was disabling all the ui elements
  but not the rate buttons.
- This fix makes the ui disable the rate buttons too, as well as showing
  a Toast, and logging the exception to logcat.
- This cl also adds the unit tests that prove that the bug is fixed.
- In the process, I discovered another bug where missing extras from
  the intent used to start the CallDetailsActivity could cause a crash,
  so this adds a test and a fix for that case too.
- Also introduces IntegrationTestUtils class, with some useful methods
  for doing things like clicking on different parts of the ui.

Bug: 5047879
Change-Id: I46d18723fe783a7a820446e1e13e19b5af82fa5c
7 files changed