Increase rt/schedtune.boost for M and S from 20 to 30

This value is the minimum that gives good results for Simple Synth.

Test: Simple Synth with test tone on, variable load on, stabilized load off,
      workload alternating between 200000 and 20000.  Underruns should be near zero.
Bug: 30210506

Change-Id: I387b6f321a0b678b2cbe567124cf9d2b9f28cd49
diff --git a/init.common.rc b/init.common.rc
index 043ee94..ddc6eac 100644
--- a/init.common.rc
+++ b/init.common.rc
@@ -84,7 +84,7 @@
     write /dev/stune/foreground/schedtune.prefer_idle 1
     write /dev/stune/top-app/schedtune.boost 10
     write /dev/stune/top-app/schedtune.prefer_idle 1
-    write /dev/stune/rt/schedtune.boost 20
+    write /dev/stune/rt/schedtune.boost 30
     write /dev/stune/rt/schedtune.prefer_idle 1
 
     # Create UDS structure for base VR services.