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/RecentsAnimation.java b/services/core/java/com/android/server/wm/RecentsAnimation.java
index 24c5228..1e287b4 100644
--- a/services/core/java/com/android/server/wm/RecentsAnimation.java
+++ b/services/core/java/com/android/server/wm/RecentsAnimation.java
@@ -148,8 +148,8 @@
                 // If there are multiple tasks in the target stack (ie. the home stack, with 3p
                 // and default launchers coexisting), then move the task to the top as a part of
                 // moving the stack to the front
-                if (targetStack.topTask() != targetActivity.getTask()) {
-                    targetStack.addTask(targetActivity.getTask(), true /* toTop */,
+                if (targetStack.topTask() != targetActivity.getTaskRecord()) {
+                    targetStack.addTask(targetActivity.getTaskRecord(), true /* toTop */,
                             "startRecentsActivity");
                 }
             } else {