Fix script-related parts of locale resource matching

Previously, a bit was kept to find if the script of a locale was
explicitly "provided" in a resource. This was not backward
compatible, and failed in some edge cases when the package was
created with older versions of AAPT that did not set the bit.

The cases would happen when the old resource had an explicit script
specified in its locale, but since the "provided" bit was not set in
the package, we would assume that the script was computed by us.

This CL replaces the "provided" bit with a "computed" bit, so the
default value of the bit (set to "false" for old packages) would be
correct.

Bug: 27156990
Change-Id: I99e7f1ad8f70c90e25ab3640ed34cc1a6f8d1d64