[Settings][DBD] Fix invalid TimePeriod selection in old dialog

If an invalid TimePeriod is selected in the old dialog, the expected
behaviour is to default to LAST_HOUR. The existing logic to check for
invalid TimePeriods checks if it matches an entry in TimePeriod enum.
This is no longer true since this enum is shared across both old and
new UIs.
The change instead checks if the TimePeriod is defined as a valid
option in the old dialog.


Bug: 431215192
Change-Id: I24392e6c3d2c07993b7fc8385ba39271eee8d11d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6728319
Auto-Submit: Zaina Al-Mashni <zalmashni@google.com>
Reviewed-by: Rainhard Findling <rainhard@chromium.org>
Commit-Queue: Zaina Al-Mashni <zalmashni@google.com>
Commit-Queue: Rainhard Findling <rainhard@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1485680}