AudioFlinger: Group common compile flags together

Test: compiles
Bug: 286936439
Merged-In: Ie15e07886e2e4fcc813b1cea18ad87bc1b892fd4
Change-Id: Ie15e07886e2e4fcc813b1cea18ad87bc1b892fd4
(cherry picked from commit 7bac54fc96ceb933a9f06e75c3c20f1df46fea5b)
3 files changed