AudioProfile: reject profile if not exact match

In AudioProfile.cpp, the checkExact() function was treating dynamic_channels as a wildcard.
So 5.1 would match even if there were no channel masks listed as supported.

Bug: 25144047
Change-Id: I3036dca7e0ed92579b1ac7a3cf8504b0e47b7ed5
Signed-off-by: Phil Burk <philburk@google.com>