Simplifying some LauncherModel logic

> Converting various if-else-if blocks to when
> Moving SessionMailureTask to its own class
> Moving install session callbacks to ModelCallbacks

Bug: 372553045
Test: Presubmit
Flag: EXEMPT refactor

Change-Id: I027b35f271b84f079fa3135b56dc15bb7375b2e0
diff --git a/src/com/android/launcher3/LauncherAppState.java b/src/com/android/launcher3/LauncherAppState.java
index 05a3a52..42a28d6 100644
--- a/src/com/android/launcher3/LauncherAppState.java
+++ b/src/com/android/launcher3/LauncherAppState.java
@@ -176,7 +176,7 @@
                     () -> LauncherPrefs.get(mContext).removeListener(observer, THEMED_ICONS));
 
             InstallSessionTracker installSessionTracker =
-                    InstallSessionHelper.INSTANCE.get(context).registerInstallTracker(mModel);
+                    InstallSessionHelper.INSTANCE.get(context).registerInstallTracker(callbacks);
             mOnTerminateCallback.add(installSessionTracker::unregister);
         });