Keep 'partition' in PackagingSpec

Add a property 'partition' to PackagingSpec and fill it when
PackagingSpec is created.

This will enable PackageModule to filter PackgingSpec based on
partition. (Will be used in a follow-up change)

Bug: 225121718
Test: m (nothing changes)
Change-Id: I7657edd380e215df66bae57d8b07dd4181841fdf

android/module.go

@@ -3119,6 +3119,7 @@ func (m *moduleContext) packageFile(fullInstallPath InstallPath, srcPath Path, e
 		symlinkTarget:         "",
 		executable:            executable,
 		effectiveLicenseFiles: &licenseFiles,
+		partition:             fullInstallPath.partition,
 	}
 	m.packagingSpecs = append(m.packagingSpecs, spec)
 	return spec
@@ -3236,6 +3237,7 @@ func (m *moduleContext) InstallSymlink(installPath InstallPath, name string, src
 		srcPath:          nil,
 		symlinkTarget:    relPath,
 		executable:       false,
+		partition:        fullInstallPath.partition,
 	})
 
 	return fullInstallPath
@@ -3276,6 +3278,7 @@ func (m *moduleContext) InstallAbsoluteSymlink(installPath InstallPath, name str
 		srcPath:          nil,
 		symlinkTarget:    absPath,
 		executable:       false,
+		partition:        fullInstallPath.partition,
 	})
 
 	return fullInstallPath