Add function for scaling haptic data.

The function was in AudioMixer. With adding haptic-generating effect,
there will be more than one place calling the scaling function. In that
case, it makes more sense to put the scaling function in vibrator
library.

Bug: 136490803
Test: play audio-coupled-haptic files
Test: play audio with attaching haptic-generating effect
Change-Id: Ia7f88463e2d2b7f11954ab9bb6aeff8191c78894
diff --git a/libs/vibrator/Android.bp b/libs/vibrator/Android.bp
index e95a080..1681fe2 100644
--- a/libs/vibrator/Android.bp
+++ b/libs/vibrator/Android.bp
@@ -14,6 +14,8 @@
 
 cc_library_shared {
     name: "libvibrator",
+    vendor_available: true,
+    double_loadable: true,
 
     shared_libs: [
         "libbinder",