Add sphal namespace to swcodec apex

Add sphal namespace for swcodec apex, and keep the search/
permitted paths in sync with system's sphal/vndk namespaces.

This change also removes libz.so from the list of shared libs
linking from default to platform namespace.

bug: 129552044
bug: 129095969

test: cts-tradefed run singleCommand cts -d --module CtsMediaTestCases --test android.media.cts.DecoderTest#testVp9HdrStaticMetadata

Change-Id: Id3148dacde43e4bd9c1782ffd67acb21ef095811