Shift IntentFilter.toString() for RAM regression.

We have a hunch that apps might have already been using toString()
here, and a recent improvement that added more debugging information
might be causing a RAM regression.

If this idea proves itself out, we can potentially bring back the
improved toString() guarded by a CompatChange.

Bug: 269579722
Test: TH
Change-Id: I05acb0d4404325b6cd6e2ca7da6383a5f45e02fe