Fix AudioMix.equals()

Use Object.equals() when comparing Objects instead of '=='

Test: Added unit tests (see topic).  Verified that test failed before changes and passed afterwards.
Change-Id: I12d8cb24207c64b96d2fe65d4b2045873b080bc3
Merged-In: I12d8cb24207c64b96d2fe65d4b2045873b080bc3
1 file changed