Change visibility of module sdk prebuilts to //visibility:public

To reduce pains introduced by visiblity skew between source
and prebuilts, mark them with //visibility:public

Bug: 239189932
Test: go test ./sdk
Change-Id: I47dd63bd03337bc9ec6fa364bbdcdfdfcd70b0d9

sdk/sdk_test.go

@@ -131,11 +131,7 @@ apex_contributions_defaults {
 java_import {
     name: "myjavalib",
     prefer: false,
-    visibility: [
-        "//other/foo",
-        "//package",
-        "//prebuilts/mysdk",
-    ],
+    visibility: ["//visibility:public"],
     apex_available: ["//apex_available:platform"],
     jars: ["java/myjavalib.jar"],
 }
@@ -151,11 +147,7 @@ java_import {
 java_import {
     name: "mydefaultedjavalib",
     prefer: false,
-    visibility: [
-        "//other/bar",
-        "//package",
-        "//prebuilts/mysdk",
-    ],
+    visibility: ["//visibility:public"],
     apex_available: ["//apex_available:platform"],
     jars: ["java/mydefaultedjavalib.jar"],
 }
@@ -163,10 +155,7 @@ java_import {
 java_import {
     name: "myprivatejavalib",
     prefer: false,
-    visibility: [
-        "//package",
-        "//prebuilts/mysdk",
-    ],
+    visibility: ["//visibility:public"],
     apex_available: ["//apex_available:platform"],
     jars: ["java/myprivatejavalib.jar"],
 }
@@ -185,28 +174,6 @@ func TestPrebuiltVisibilityProperty_IsValidated(t *testing.T) {
 `)
 }
 
-func TestPrebuiltVisibilityProperty_AddPrivate(t *testing.T) {
-	testSdkError(t, `prebuilt_visibility: "//visibility:private" does not widen the visibility`, `
-		sdk {
-			name: "mysdk",
-			prebuilt_visibility: [
-				"//visibility:private",
-			],
-			java_header_libs: [
-				"myjavalib",
-			],
-		}
-
-		java_library {
-			name: "myjavalib",
-			// Uses package default visibility
-			srcs: ["Test.java"],
-			system_modules: "none",
-			sdk_version: "none",
-		}
-`)
-}
-
 func TestSdkInstall(t *testing.T) {
 	sdk := `
 		sdk {

sdk/update.go

@@ -1109,20 +1109,22 @@ func (s *snapshotBuilder) AddPrebuiltModule(member android.SdkMember, moduleType
 		// same package so can be marked as private.
 		m.AddProperty("visibility", []string{"//visibility:private"})
 	} else {
-		// Extract visibility information from a member variant. All variants have the same
-		// visibility so it doesn't matter which one is used.
-		visibilityRules := android.EffectiveVisibilityRules(s.ctx, variant)
-
-		// Add any additional visibility rules needed for the prebuilts to reference each other.
-		err := visibilityRules.Widen(s.sdk.properties.Prebuilt_visibility)
-		if err != nil {
-			s.ctx.PropertyErrorf("prebuilt_visibility", "%s", err)
-		}
-
-		visibility := visibilityRules.Strings()
-		if len(visibility) != 0 {
-			m.AddProperty("visibility", visibility)
-		}
+		// Change the visibility of the module SDK prebuilts to public.
+		// This includes
+		// 1. Stub libraries of `sdk` modules
+		// 2. Binaries and libraries of `module_exports` modules
+		//
+		// This is a workaround to improve maintainlibility of the module SDK.
+		// Since module sdks are generated from release branches and dropped to development
+		// branches, there might be a visibility skew between the sources and prebuilts
+		// of a specific module.
+		// To reconcile this potential skew, change the visibility to public
+		//
+		// This is safe for (1) since these are stub libraries.
+		// This is ok for (2) since these are host and test exports and are intended for
+		// ART development.
+		// TODO (b/361303067): This can be removed if ART uses full manifests.
+		m.AddProperty("visibility", []string{"//visibility:public"})
 	}
 
 	// Where available copy apex_available properties from the member.