If a resource XML file defines two compatible Attributes, they should
be merged without throwing an error. Ex:
<declare-styleable>
<attr name="conflict" format="string" />
</declare-styleable>
<declare-styleable>
<attr name="conflict" format="string|reference" />
</declare-styleable>
In this case, string|reference and string are the same, so these should
merge correctly.
Bug: 65699599
Test: make aapt2_tests
Test: make AaptBasicTest
Change-Id: I7b0f956d2332f7f0b458acd59ca0a606b2cfdf95
73bff1e851