Add EXTRA_START_PLAYBACK

This is used to indicate that media should start playing immediately.

Bug: 34813647
Test: build
Change-Id: If1414ef0912070496934a1199d45970a932d6d27
diff --git a/api/current.txt b/api/current.txt
index 5eeacba..67b2b71 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -5489,6 +5489,7 @@
     field public static final java.lang.String EXTRA_CHANGED_PACKAGE_LIST = "android.intent.extra.changed_package_list";
     field public static final java.lang.String EXTRA_CHANGED_UID_LIST = "android.intent.extra.changed_uid_list";
     field public static final java.lang.String EXTRA_HTML_TEXT = "android.intent.extra.HTML_TEXT";
+    field public static final java.lang.String EXTRA_START_PLAYBACK = "android.intent.extra.START_PLAYBACK";
     field public static final int FLAG_ACTIVITY_CLEAR_TASK = 32768; // 0x8000
     field public static final int FLAG_ACTIVITY_TASK_ON_HOME = 16384; // 0x4000
   }