Refactoring Audio Frequency tests.

Clean up UI management.
Remove unused imports.
Better use of inheritance.
Preparing for Device Connection Listener logic.

Bug: 150298815
Test: build, run, verify

Change-Id: I2470e209f75d7b9b144f03c5bf746868902bbcb2
Merged-In: I2470e209f75d7b9b144f03c5bf746868902bbcb2
8 files changed