8659 Replace ThreadLocal with ThreadLocalUniquePtr (cla: yes)

8661 Put the testing lib in the flutter namespace. (cla: yes)

8663 Remove support for downloading dynamic patches on Android (cla: yes)

8664 Add framework test in engine presubmit checks (cla: yes)

8681 Revert “Custom RTL handling for ghost runs, NotoNaskhArabic test font” (cla: yes)

8682 Revert “Only allow mappings for ICU initialization.” (cla: yes)

8683 Custom RTL handling for ghost runs, NotoNaskhArabic test font (cla: yes)

8688 fix toString (cla: yes)

8689 Revert “Remove unused Settings::ToString. (#8642)” (cla: yes)