Don't use zip files when creating filesystems

The end result is a directory that's passed to build_image, so zipping
and then unzipping image contents will unnecessarily slow things down.

Bug: 329146343
Test: m microdroid --no-skip-soong-tests
Change-Id: I98223c60e8144d6c707832fcc03ba8fe94467e7b
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 19b9d16..add6083 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -11022,7 +11022,7 @@
 		}
 	`)
 
-	inputs := result.ModuleForTests("myfilesystem", "android_common").Output("deps.zip").Implicits
+	inputs := result.ModuleForTests("myfilesystem", "android_common").Output("myfilesystem.img").Implicits
 	android.AssertStringListDoesNotContain(t, "filesystem should not have libbar",
 		inputs.Strings(),
 		"out/soong/.intermediates/libbar/android_arm64_armv8-a_shared/libbar.so")