Reland "Treat input files as public API."

Input files are public API:
https://source.android.com/devices/input/input-device-configuration-files
Now that they have labels from core policy (aosp/782082), we can tighten
up our neverallows.

Bug: 37168747
Test: m selinux_policy
Change-Id: Ifaf9547993eb8c701fb63b7ee41971ea4e3f7cf9

public/domain.te

@@ -1130,7 +1130,6 @@ full_treble_only(`
     userdebug_or_eng(`-perfprofd')
     -shell
     -system_executes_vendor_violators
-    -system_server # reads vendor input files
     -ueventd # reads /vendor/ueventd.rc
   } {
     vendor_file_type
@@ -1138,6 +1137,9 @@ full_treble_only(`
     -vendor_app_file
     -vendor_configs_file
     -vendor_framework_file
+    -vendor_idc_file
+    -vendor_keychars_file
+    -vendor_keylayout_file
     -vendor_overlay_file
     -vendor_public_lib_file
     -vndk_sp_file