Tests for ThrottleService, NTP into TrustedTime.

Wrote initial suite of tests for ThrottleService, checking a variety
of edge cases.  Checks going over limits, updating policies, and reset
after cycle elapses.

Moved NTP code in ThrottleService into new TrustedTime interface,
which makes it easier to understand, and allows tests to provide custom
clocks.

Change-Id: I0d62b8b3a169516a2ab2d33025f6fe30dc792be8
diff --git a/services/tests/servicestests/Android.mk b/services/tests/servicestests/Android.mk
index 186b349..295f324 100644
--- a/services/tests/servicestests/Android.mk
+++ b/services/tests/servicestests/Android.mk
@@ -7,7 +7,9 @@
 # Include all test java files.
 LOCAL_SRC_FILES := $(call all-java-files-under, src)
 
-LOCAL_STATIC_JAVA_LIBRARIES := easymocklib
+LOCAL_STATIC_JAVA_LIBRARIES := \
+    easymocklib \
+    guava
 
 LOCAL_JAVA_LIBRARIES := android.test.runner services