libstagefright: Reset flac decoder eos during flush

- The CTS test case testDecodeFlac fails when the reset mode
  is RESET_MODE_EOS_FLUSH.
- In this mode, after input and output eos are set, there is a seek to 0
  but bit-stream is not fetched from the parser resulting in an
  assert that causes the CTS failure.
- Ensure that the decoder eos is reset in flushDecoder so that bit-stream
  is fetched from the parser.
- Also fix indentation issues for log messages.

CRs-Fixed: 793060
Change-Id: I5fc86a7b04f009e91231fa4b20b32da1dac6a9ca