libstagefright/exports.lds: Use regex pattern for some functions

With the updated libyuv, not having the regex pattern results in a
linker error.

Example:

ld.lld: error: version script assignment of 'local' to symbol
'ABGRToI420' failed: symbol not defined

Bug: b/241008246
Test: Builds. Camera and Media CTS tests pass.
Merged-In: I6ed572241ba4beeead0cc8932148bfd83e4a6869
Change-Id: I87523fcce60a2a014918ade888ce8a308db21cf8