Switch some objects in WmTest to use spyOn()

Helps reduce the complexity of test setup as spyOn()
allows spying on an object without creating a wrapper clone
of it

Bug: 113806960
Bug: 119830111
Test: Existing tests pass.
Change-Id: I6e7f8b6f728b5fffe90f34e42256fd0970037917
diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index 1d00075..30eb500 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -341,7 +341,8 @@
     ActivityManagerInternal mAmInternal;
     UriGrantsManagerInternal mUgmInternal;
     private PackageManagerInternal mPmInternal;
-    private ActivityTaskManagerInternal mInternal;
+    @VisibleForTesting
+    final ActivityTaskManagerInternal mInternal;
     PowerManagerInternal mPowerManagerInternal;
     private UsageStatsManagerInternal mUsageStatsInternal;
 
@@ -643,6 +644,7 @@
         mSystemThread = ActivityThread.currentActivityThread();
         mUiContext = mSystemThread.getSystemUiContext();
         mLifecycleManager = new ClientLifecycleManager();
+        mInternal = new LocalService();
         GL_ES_VERSION = SystemProperties.getInt("ro.opengles.version", GL_ES_VERSION_UNDEFINED);
     }
 
@@ -893,7 +895,6 @@
     }
 
     private void start() {
-        mInternal = new LocalService();
         LocalServices.addService(ActivityTaskManagerInternal.class, mInternal);
     }
 
@@ -6870,4 +6871,4 @@
             }
         }
     }
-}
\ No newline at end of file
+}