aacenc: handle input size not aligned at sample boundary

Bug: 136068046
Bug: 142699551
Test: modified EncoderTest
Change-Id: Ife09efcedf573d4327e8482e03dd82fcafdb5eb2
Merged-In: Ife09efcedf573d4327e8482e03dd82fcafdb5eb2
(cherry picked from commit 3dd7bd3440ef048fa0fcd9d86c42ac75038e9c11)
2 files changed