EffectHalAidl: fix the input/output buffer reading size

the actual framecount in EffectBufferHalInterface could be smaller than
allocated buffer size
cleanup and split the process code

Flag: EXEMPT bugfix
Bug: 363428226
Test: atest AudioEffectTest CtsMediaAudioTestCases audioeffect_analysis
Test: HapticGenerator testing APP

Change-Id: I1f2808b20fe084935e0b77a38b8b0d4ed9b52f6b
Merged-In: I1f2808b20fe084935e0b77a38b8b0d4ed9b52f6b