Revert "Bug 957100 - [Settings] add marionette for b2g-improve and feedback page"

This reverts commit 0b49a29ae694f55333ab2a0054d85597a3e5582d.
Merge pull request #15415 from KevinGrandon/revert_pr_15065

Revert "Bug 957100 - [Settings] add marionette for b2g-improve and feedback page"