stagefright-plugins: Correctly check if audio codec is open
stagefright-plugins: Correctly check if audio codec is open

 * Same as we're doing for video.

Change-Id: I424cdd197cae73d0647738fc9c97e87c2692181b

AOSPB/external_stagefright-plugins,AOSP-CAF/platform_external_stagefright-plugins,BrokenROM/external_stagefright-plugins,TeamExodus/external_stagefright-plugins,SlimRoms/android_external_stagefright-plugins,AOSPB/external_stagefright-plugins,BrokenROM/external_stagefright-plugins,SlimRoms/android_external_stagefright-plugins,DirtyUnicorns/android_external_stagefright-plugins,PAC-ROM/android_external_stagefright-plugins,VRToxin/android_external_stagefright-plugins,AOSP-CAF/platform_external_stagefright-plugins,Evervolv/android_external_stagefright-plugins,Evervolv/android_external_stagefright-plugins,PAC-ROM/android_external_stagefright-plugins,VRToxin/android_external_stagefright-plugins,TeamExodus/external_stagefright-plugins,DirtyUnicorns/android_external_stagefright-plugins