Move InputFeature flag definitions to AIDL (1/2)

We convert the InputFeatures flags into AIDL enums that will have values
generated in both native and java code so that the value only has to be
defined once.

Bug: 162194035
Test: build, presubmit
Change-Id: I28bd51a4affe705155c08c273a902d86665c63b9
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index c5dec19..9488c0a 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -66,6 +66,7 @@
     host_supported: true,
     srcs: [
         ":guiconstants_aidl",
+        ":inputconstants_aidl",
         "android/gui/DisplayInfo.aidl",
         "android/gui/FocusRequest.aidl",
         "android/gui/InputApplicationInfo.aidl",