Fix for bug #7417949 TextView / EditText error Drawable is not put on the left in RTL mode

- keep the Error Drawable infos into the Drawables cache
- reset left/right Drawable state before resolving where to put the Error Drawable
- get the mirrored Drawable for the Error popup background
- set the Error popup position depending on the layout direction (so that the "triangle"
of the background is pointing to the middle of the Error icon)

One restriction: we load the Error popup background Drawable corresponding to the layout
direction of the System Locale. So if you set the Layout direction on a TextView (or
an EditText) to RTL and set an error to it when you are in a RTL System Locale, then you
see that the background "triangle" is not pointing to the Error icon. This is working as
intended as the AssetManager load the Drawable resource depending on the configuration
which is in that case the RTL one thus loading the RTL version of the background (and not
the LTR one).

Thus there can be a discrepancy between the "layout direction" of the TextView
and the one from the Error popup background. This would happen only thru using the SDK and
not in a normal case when running an App.

Change-Id: I91bbfbe46ac20efe0e585c5d4c766db23b5c709d
22 files changed