Use correct size of GAMEPAD_KEYCODES

Compute the actual number of indices in the GAMEPAD_KEYCODES instead of
the pure size in bytes.

Bug: 3121536
Change-Id: I71edbd8bf6eff2c8cc0ea5c6845362b3d1e06466
diff --git a/libs/ui/EventHub.cpp b/libs/ui/EventHub.cpp
index 944731d..5c618fb 100644
--- a/libs/ui/EventHub.cpp
+++ b/libs/ui/EventHub.cpp
@@ -818,7 +818,7 @@
         }
         
         // See if this device has a gamepad.
-        for (size_t i = 0; i < sizeof(GAMEPAD_KEYCODES); i++) {
+        for (size_t i = 0; i < sizeof(GAMEPAD_KEYCODES)/sizeof(GAMEPAD_KEYCODES[0]); i++) {
             if (hasKeycodeLocked(device, GAMEPAD_KEYCODES[i])) {
                 device->classes |= INPUT_DEVICE_CLASS_GAMEPAD;
                 break;