Codec2: Fix initial values in output C2Work

Ensures that the initial values of result field in C2Work,
flags and ordinals of input and output C2FrameData is updated properly
in all code paths

Bug: 346689283
Test: atest android.mediav2.cts.CodecDecoderMultiAccessUnitTest
Flag: EXEMPT BugFix
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:a82a42b5f49ad10547fbf06fbd4ea572954f1248)
Merged-In: I6bd4e5cb6b0e27361f95614329318e2c53e5062e
Change-Id: I6bd4e5cb6b0e27361f95614329318e2c53e5062e