manifest_check.py: Clarify that ordering matters

When comparing the library declaration from AndroidManifest.xml and
Android.bp, the library ordering must match (see b/132357300#comment3).
The error message does not make it clear that ordering is significant
and a mismatch in ordering is an error.

Improve the error message to make this more obvious.

Bug: 401287317
Test: compiles
Change-Id: Idfb3e1e96893f81190dc320c49d40677b76f9853