libstagefright: fix metadata key sizes

 - some wma metadata keys should be treated as 32 bit keys instead
   of 64 bits.
 - fixes wma lossless from failing

Change-Id: Ic6af8392aea6a1bd8810dac59e1d1c27c21c4059
(cherry picked from commit 1fae0bcb8ef9244e1f28d21c36e388ab365e3c0f)
(cherry picked from commit 97be73e3004a838227060f026f38c7231dd7e2f7)
(cherry picked from commit 4d24c91e49c89eadb7b48e47e38a9b7b6df8f1cf)