Fix memory leak in MediaProjectionPermissionActivity

As stated in SystemUIDialog#registerDismissListener,
"Don't call dialog.setOnDismissListener() after calling
this because it causes a leak of BroadcastReceiver."

So here we go, using "the version that takes an extra
Runnable as a parameter."

Bug: 434681474
Flag: EXEMPT BUGFIX
Test: Manually and checked the heap dump
Change-Id: Ia3b9d6562b1dd158b14fa4e0c2071ca1fad4e4ff