webkit: SystemImpl: Make systemIsDebuggable() check IS_ENG as well

* Since we are shipping userdebug builds by default
  it'd be nice to keep signature and version downgrade
  checks intact.
* Fixes : https://gitlab.com/LineageOS/issues/android/-/issues/2192

Change-Id: Ib46ccb50ac091469caf99a73a5a08942cbc457f6
1 file changed