make libaudioutils_fixedfft vendor_available:true

This, when used with BOARD_VNDK_VERSION flag, enables the
module to be built and installed twice, one for /system,
other for /vendor.

libaudioutils_fixedfft is used by libaudioutils which is in turn used by libs in
/vendor and thus marked as vendor_available. Therefore, libaudioutils_fixedfft
is also marked as vendor_available.

Details: https://android-review.googlesource.com/368372

Bug: 33241851
Test: BOARD_VNDK_VERSION=current m libaudioutils_fixedfft.vendor successful
Change-Id: Ic594eeb153b90ee45e7b5d9b682af9c3ff5471e4
diff --git a/audio_utils/Android.bp b/audio_utils/Android.bp
index 95216ce..713ae2b 100644
--- a/audio_utils/Android.bp
+++ b/audio_utils/Android.bp
@@ -58,6 +58,7 @@
 
 cc_library_static {
     name: "libaudioutils_fixedfft",
+    vendor_available: true,
     defaults: ["audio_utils_defaults"],
 
     arch: {