Support custom effect type UUID in audio effect AIDL example service

Parse custom effect type uuid in audio_effects_config.xml, so OEM can
add effect types without changing code

Bug: 271500140
Test: atest --test-mapping hardware/interfaces/audio/aidl/vts:presubmit
(cherry picked from https://android-review.googlesource.com/q/commit:80e5850d82f1b311a89367a77bab2c801ac16b37)
Merged-In: I558958cc42c6c4a304e0ab1239ddefec9575a5af
Change-Id: I558958cc42c6c4a304e0ab1239ddefec9575a5af