Recycle ActivityStarter instances.

This changelist adds the ability to reuse ActivityStarter instances
by reclaiming spent ones. By default, ActivityStarters will now be
reset and be part of a pool for future activity start uses.

Bug: 64750076
Test: atest FrameworksServicesTests:StartActivityControllerTests
Test: atest FrameworksServicesTests:ActivityStarterTests

Change-Id: I77261ba6f397471f4aeb9ef6dfe5edcf55f0007f
diff --git a/services/tests/servicestests/src/com/android/server/am/ActivityStarterTests.java b/services/tests/servicestests/src/com/android/server/am/ActivityStarterTests.java
index e8194dd..589a89b 100644
--- a/services/tests/servicestests/src/com/android/server/am/ActivityStarterTests.java
+++ b/services/tests/servicestests/src/com/android/server/am/ActivityStarterTests.java
@@ -63,6 +63,7 @@
 import static android.app.ActivityManager.START_INTENT_NOT_RESOLVED;
 
 import com.android.internal.os.BatteryStatsImpl;
+import com.android.server.am.ActivityStarter.Factory;
 
 /**
  * Tests for the {@link ActivityStarter} class.