Fix race condition for VQDS functionalities

Lock are missing for thread safety on major VQDS functions.
These methods can be invoked consecutively and race condition can
happen. We need to add a lock to prevent it from happening.

Bug: 295390470
Test: atest CtsVoiceInteractionTestCases
Flag: N/A
Change-Id: I99c43deb024f2d5fee5c1ac12e549966f949dc1e