Framework support to improve bg check CTS tests.

(Finally) introduce a new ServiceConnection callback to
tell you when the binding has died.  This allows you to robustly
have a weak service monitoring, and also is an easy way to find
out about breakages due to app updates etc.

Also clean up some debug output.

Test: moved to own suite and ran them.

Change-Id: I526cc00816c384fa9eb1312b92406f38085cbff9
diff --git a/services/core/java/com/android/server/am/ProcessRecord.java b/services/core/java/com/android/server/am/ProcessRecord.java
index 2d27204..3c5c5fd 100644
--- a/services/core/java/com/android/server/am/ProcessRecord.java
+++ b/services/core/java/com/android/server/am/ProcessRecord.java
@@ -287,7 +287,9 @@
                 pw.print(" setSchedGroup="); pw.print(setSchedGroup);
                 pw.print(" systemNoUi="); pw.print(systemNoUi);
                 pw.print(" trimMemoryLevel="); pw.println(trimMemoryLevel);
-        pw.print(prefix); pw.print("vrThreadTid="); pw.print(vrThreadTid);
+        if (vrThreadTid != 0) {
+            pw.print(prefix); pw.print("vrThreadTid="); pw.println(vrThreadTid);
+        }
         pw.print(prefix); pw.print("curProcState="); pw.print(curProcState);
                 pw.print(" repProcState="); pw.print(repProcState);
                 pw.print(" pssProcState="); pw.print(pssProcState);