Add android_system_image_defaults

Bug: 330665150
Test: go test ./... under filesystem
Change-Id: Id32e6563491a3d129042de4a9517c545543a022d

filesystem/filesystem_test.go

@@ -364,3 +364,72 @@ func TestFileSystemWithCoverageVariants(t *testing.T) {
 		t.Error("prebuilt should use cov variant of filesystem")
 	}
 }
+
+func TestSystemImageDefaults(t *testing.T) {
+	result := fixture.RunTestWithBp(t, `
+		android_system_image_defaults {
+			name: "defaults",
+			multilib: {
+				common: {
+					deps: [
+						"phony",
+					],
+				},
+				lib64: {
+					deps: [
+						"libbar",
+					],
+				},
+			},
+			compile_multilib: "both",
+		}
+
+		android_system_image {
+			name: "system",
+			defaults: ["defaults"],
+			multilib: {
+				lib32: {
+					deps: [
+						"foo",
+						"libbar",
+					],
+				},
+			},
+		}
+
+		cc_binary {
+			name: "foo",
+			compile_multilib: "prefer32",
+		}
+
+		cc_library {
+			name: "libbar",
+			required: ["libbaz"],
+		}
+
+		cc_library {
+			name: "libbaz",
+		}
+
+		phony {
+			name: "phony",
+			required: ["libquz"],
+		}
+
+		cc_library {
+			name: "libquz",
+		}
+	`)
+
+	fs := result.ModuleForTests("system", "android_common").Module().(*systemImage)
+	expected := []string{
+		"bin/foo",
+		"lib/libbar.so",
+		"lib64/libbar.so",
+		"lib64/libbaz.so",
+		"lib64/libquz.so",
+	}
+	for _, e := range expected {
+		android.AssertStringListContains(t, "missing entry", fs.entries, e)
+	}
+}