[Tab Groups] Remove TabGroupParityAndroid flag in some tests

- Remove TAB_GROUP_PARITY from @enabledfeatures/disabledfeatures
  annotation. Removed annotations if necessary
- Delete @disabledfeatures tests that include TAB_GROUP_PARITY on
  the test level
- Removed unused imports

Bug: 365066135
Change-Id: I4f2864efb768c0fb472de411bb490b5bfca98660
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5973213
Commit-Queue: Fiaz Muhammad <mfiaz@google.com>
Reviewed-by: Calder Kitagawa <ckitagawa@chromium.org>
Reviewed-by: Sky Malice <skym@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1375408}