Fix the string reference equality comparison in MusicFxHelper

Bug: 332981866
Test: atest com.android.server.audio.MusicFxHelperTest
Flag: NONE, impact of this fix is limited
Change-Id: I996951c7f71678c76afec78efd452b275f17213e
(cherry picked from commit 52c9b6524203942d714cba0315d82f230c5015d2)
Merged-In: I996951c7f71678c76afec78efd452b275f17213e
2 files changed