mediaextractor: Skip setting memory limits on ASan builds

ASan-ified libraries have a larger memory footprint which counts
towards a process's RLIMIT_AS. Detect ASan at runtime and skip
setting memory limits.

Test: Builds and boots. "MediaUtils: running with ASan, not setting
memory limits" appears in logcat, mediaextractor is no longer
crashing.

(cherry picked from commit 4bc7ad9e)

Bug: 31831213
Change-Id: I6705baa825cbfd45695def2cd80d8d2261b05339