The Global.Setting was previously named angle_in_use_dialog_box, which
doesn't match some of the other variables and uses on the Android side.
This change will update it to show_angle_in_use_dialog_box to make
everything match both here and where it's used within Android.

Bug: angleproject:3006
Test: Load an app with ANGLE enabled and verify dialog box is shown.
Test: Load an app without ANGLE and verify dialog box is not shown.
Change-Id: I808ebc94f706a019eca6f3911a702853642926e0
Reviewed-on: https://chromium-review.googlesource.com/c/1410286Reviewed-by: Courtney Goeltzenleuchter <courtneygo@google.com>
Commit-Queue: Tim Van Patten <timvp@google.com>