Dynamically assemble the list of python launcher shared libs for precompiling

Still fall back to the hardcoded list for what to put in LOCAL_SHARED_LIBRARIES,
because I couldn't figure out a good way to get those modules at the moment.

Bug: 259718110
Test: Presubmits
Change-Id: Ia992ffea8819d8c67280b08bc45505f77af09de0

android/packaging.go

@@ -73,6 +73,10 @@ func (p *PackagingSpec) Partition() string {
 	return p.partition
 }
 
+func (p *PackagingSpec) SrcPath() Path {
+	return p.srcPath
+}
+
 type PackageModule interface {
 	Module
 	packagingBase() *PackagingBase