Audio: Increase FCC limit to 12

AudioTrackTest and AudioRecordTest will automatically
check higher channel counts if enabled.
Tested on Focusrite Scarlett 18i20 with legacy USB HAL.

Test: Clarity with 12 channels AudioTrack and effects
Test: AudioTrackTest AudioRecordTest
Bug: 192662969
Change-Id: Id371b3d87d734690532004c6f03438e556447127
diff --git a/audio/include/system/audio.h b/audio/include/system/audio.h
index 215193c..b411041 100644
--- a/audio/include/system/audio.h
+++ b/audio/include/system/audio.h
@@ -222,7 +222,7 @@
     //
     // This can be adjusted onto a value such as FCC_12 or FCC_24
     // if the device HAL can support it.  Do not reduce below FCC_8.
-    FCC_LIMIT = FCC_8,
+    FCC_LIMIT = FCC_12,
 };
 
 /* A channel mask per se only defines the presence or absence of a channel, not the order.