Move some QUICHE presubmit checks from individual files to METADATA.common.

Also add "check_delta_only: false" to make sure entire files are scanned.  I
verified that all existing files comply (or added the non-compliant ones as
exclusions).

Of the new path exclusions, the ones I intend to fix immediately I marked with a
TODO with my name.  One that is pending a flag deprecation is marked with a TODO
and a bug number.  The rest I do not intend to fix, but moving them to
METADATA.common so that they apply to all new code, not only a proper subset, is
an improvement anyway.

PiperOrigin-RevId: 448330048

quiche/http2/test_tools/random_decoder_test_base.h

diff --git a/quiche/http2/test_tools/random_decoder_test_base.h b/quiche/http2/test_tools/random_decoder_test_base.h
index b0d4dcf..ba137b3 100644
--- a/quiche/http2/test_tools/random_decoder_test_base.h
+++ b/quiche/http2/test_tools/random_decoder_test_base.h
@@ -75,10 +75,6 @@
   RandomDecoderTest();
 
  protected:
-  // TODO(jamessynge): Modify StartDecoding, etc. to (somehow) return
-  // AssertionResult so that the HTTP2_VERIFY_* methods exported from
-  // gunit_helpers.h can be widely used.
-
   // Start decoding; call allows sub-class to Reset the decoder, or deal with
   // the first byte if that is done in a unique fashion.  Might be called with
   // a zero byte buffer.