codec2 components: merge WorkQueue and PendingWork

Bug: 126621696
Test: /data/nativetest64/VtsHidlC2V1_0TargetAudioDecTest/VtsHidlC2V1_0TargetAudioDecTest --gtest_repeat=50 -I software -C c2.android.aac.decoder -P /sdcard/res/
Change-Id: I78b627b083821be313e67fdba6958c9af369687a
2 files changed