Update metrics to make UseMultipleOverlays study comparison easier

- Add NumQuadsConsidered metric to see how much work the
  OverlayProcessor has to do
- NumOverlaysPromoted is now called in all paths
- NumOverlaysAttempted/Failed are still AttemptMultipleOverlaysPath only
  - An apples to apples comparison wasn't possible, or meaningful
  - Failed is now called whenever Attempted is called to make
    comparisons easier
- OverlayStrategy metric is now updated properly for each overlay
  promoted on the multiple overlays path
- HardwareCapabilities now distinguishes between an invalid response and
  a valid response that 0 overlays are supported.
- Add HardwareCapabilitiesIsValid to see often this occurs
- MaxOverlaysSupported metric is only called for valid responses, making
  it easier to figure what hardware support looks like.

Change-Id: I855a8c7d6e77752758f536007de3fdc418d0ad77
Bug: 1309648
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3649359
Reviewed-by: Robert Kroeger <rjkroege@chromium.org>
Commit-Queue: Kevin Haslett <khaslett@chromium.org>
Reviewed-by: Jonathan Ross <jonross@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1007084}