Add "uinput" command to support uinput device.

Add support of uinput device with "uinput" shell command, allows user to
create a virtual uinput device and inject events to it, for input
framework testing.

Bug: 160360195
Bug: 163217897

Test: run uinput command from adb shell.
Change-Id: Ic885ae510d98fa282722f7a17d66778c15a893b6
diff --git a/PREUPLOAD.cfg b/PREUPLOAD.cfg
index 2fd2e33..fc5efc6 100644
--- a/PREUPLOAD.cfg
+++ b/PREUPLOAD.cfg
@@ -6,6 +6,7 @@
 clang_format = --commit ${PREUPLOAD_COMMIT} --style file --extensions c,h,cc,cpp
                cmds/hid/
                cmds/input/
+               cmds/uinput/
                core/jni/
                libs/input/
                services/core/jni/