[INTERNAL] m.InputBase: don't set the default state for "aria-disabled"

- According to the specification, the default state for "aria-disabled"
don't need to be set explicitly

- Adapts and moves unit tests from m.ComboBox to m.InputBase

Change-Id: I14079a28e97ed6244bde75e73138bc82360628a0
Merge "[INTERNAL] m.InputBase: don't set the default state for "aria-disabled""