Print extra error code if LDAC encoder fails to initialize

Also, add a missing CHECK() assert that the LDAC handle is valid.

Bug: 79675742
Test: Code compilation
Change-Id: I4bd51ed978eadc2aecc27d199e6f01bb31c9a631
Merged-In: I4bd51ed978eadc2aecc27d199e6f01bb31c9a631
(cherry picked from commit d963d2b2827aa6f1638eaa87597f28bb9d7a88d4)