Android: Fix a bug not supporting gamepad

https://crrev.com/c/1135874 left out checking gamepad events
by mistake. This CL fixes it by adding the check against
GenericMotionEvent in the content ui event handler.

Tested on https://html5gamepad.com with a USB gamepad.

TBR=boliu@chromium.org

Bug: 906347
Change-Id: I2bd0890f2533e70a772dbb0b005d69bf086d1595
Reviewed-on: https://chromium-review.googlesource.com/c/1356727
Reviewed-by: Bo <boliu@chromium.org>
Commit-Queue: Jinsuk Kim <jinsukkim@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#613268}(cherry picked from commit 00ebecafc6766ac90c9d50ecf8c28a1441a053d3)
Reviewed-on: https://chromium-review.googlesource.com/c/1361750
Reviewed-by: Jinsuk Kim <jinsukkim@chromium.org>
Cr-Commit-Position: refs/branch-heads/3626@{#58}
Cr-Branched-From: d897fb137fbaaa9355c0c93124cc048824eb1e65-refs/heads/master@{#612437}
2 files changed