b/12068020 Make kb layouts only unique to vendor/product. Do not merge

This is a cherry-pick of https://googleplex-android-review.git.corp.google.com/#/c/399886/

Instead of storing a kb layout per device descriptor (which is expected
to be unique), store it for each vendor/product. This way we can keep
a consistent layout between identical but physically different keyboards.

There are some corner cases this is expected to fail on, namely devices
that incorrectly have the same vendor/product id. Devices that don't
define a vendor/product id will continue to use the descriptor to store
layout files.

Change-Id: I1f2508561992080459310d5a644dad65a9c24f1a
diff --git a/libs/input/InputReader.h b/libs/input/InputReader.h
index eb5746b..6b5ce34 100644
--- a/libs/input/InputReader.h
+++ b/libs/input/InputReader.h
@@ -281,7 +281,8 @@
     virtual void notifyInputDevicesChanged(const Vector<InputDeviceInfo>& inputDevices) = 0;
 
     /* Gets the keyboard layout for a particular input device. */
-    virtual sp<KeyCharacterMap> getKeyboardLayoutOverlay(const String8& inputDeviceDescriptor) = 0;
+    virtual sp<KeyCharacterMap> getKeyboardLayoutOverlay(
+            const InputDeviceIdentifier& identifier) = 0;
 
     /* Gets a user-supplied alias for a particular input device, or an empty string if none. */
     virtual String8 getDeviceAlias(const InputDeviceIdentifier& identifier) = 0;