Renamed a few methods in ActivityRecord (42/n).

This is in preparation for having the ActivityRecord class
extend AppWindowToken where name distinction will be important.
There is no functional change in this CL.

ActivityRecord.realActivity -> mActivityComponent
ActivityRecord.userId -> mUserId
ActivityRecord.getTask() -> getTaskRecord()
ActivityRecord.getStack() -> getActivityStack()
ActivityRecord.service -> mAtmService
WindowContainer.mService -> mWmService

Bug: 80414790
Test: Existing tests pass.
Change-Id: Ie5788db7f2e823c7d5b64c7ce6eaade1c19c4dcd
diff --git a/services/core/java/com/android/server/wm/Task.java b/services/core/java/com/android/server/wm/Task.java
index 6904ef5..d3db5df 100644
--- a/services/core/java/com/android/server/wm/Task.java
+++ b/services/core/java/com/android/server/wm/Task.java
@@ -332,7 +332,7 @@
 
     boolean isResizeable() {
         return ActivityInfo.isResizeableMode(mResizeMode) || mSupportsPictureInPicture
-                || mService.mForceResizableTasks;
+                || mWmService.mForceResizableTasks;
     }
 
     /**
@@ -581,7 +581,7 @@
     }
 
     boolean isTaskAnimating() {
-        final RecentsAnimationController recentsAnim = mService.getRecentsAnimationController();
+        final RecentsAnimationController recentsAnim = mWmService.getRecentsAnimationController();
         if (recentsAnim != null) {
             if (recentsAnim.isAnimatingTask(this)) {
                 return true;
@@ -628,13 +628,13 @@
     }
 
     void forceWindowsScaleable(boolean force) {
-        mService.openSurfaceTransaction();
+        mWmService.openSurfaceTransaction();
         try {
             for (int i = mChildren.size() - 1; i >= 0; i--) {
                 mChildren.get(i).forceWindowsScaleableInTransaction(force);
             }
         } finally {
-            mService.closeSurfaceTransaction("forceWindowsScaleable");
+            mWmService.closeSurfaceTransaction("forceWindowsScaleable");
         }
     }