OWNERS: add philburk@

So I can work on MIDI services.

Test: review the file
Change-Id: I0b4b82fd31951a0510a87a1ac4fb74869a134676
diff --git a/media/OWNERS b/media/OWNERS
index be60583..242ff28 100644
--- a/media/OWNERS
+++ b/media/OWNERS
@@ -14,6 +14,7 @@
 klhyun@google.com
 lajos@google.com
 marcone@google.com
+philburk@google.com
 sungsoo@google.com
 wjia@google.com