Change QPACK fuzzers to use ConsumeIntegral*().

Change QPACK fuzzers to use templated
QuicFuzzedDataProvider::ConsumeIntegral*().  This is necessary as other
Consume* methods were removed at https://crrev.com/c/1351483, but since
these fuzzer targets were not actually included in BUILD.gn, no one
noticed that they do not compile any more.

This CL lands internal change 225596681.

Change-Id: I45094ea86949c5b94eeedd0b1a07aa125816c79d
Reviewed-on: https://chromium-review.googlesource.com/c/1378644
Commit-Queue: Ryan Hamilton <rch@chromium.org>
Reviewed-by: Ryan Hamilton <rch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#617018}
4 files changed