Revert^2 "Restrict java_sdk_library in libs of java_import and droidstubs modules"

These are all remaining usages of "magic", which are being removed with
this change. The follow up change will remove the "magic".

Test: m nothing --no-skip-soong-tests
Bug: 366069293
Change-Id: If432cdc6621ac00564e14acbaefca53db1723686
diff --git a/java/java.go b/java/java.go
index d63bbe6..b6d6173 100644
--- a/java/java.go
+++ b/java/java.go
@@ -2700,13 +2700,13 @@
 					transitiveBootClasspathHeaderJars = append(transitiveBootClasspathHeaderJars, dep.TransitiveStaticLibsHeaderJars)
 				}
 			}
-		} else if dep, ok := module.(SdkLibraryDependency); ok {
+		} else if _, ok := module.(SdkLibraryDependency); ok {
 			switch tag {
 			case libTag, sdkLibTag:
-				depHeaderJars := dep.SdkHeaderJars(ctx, j.SdkVersion(ctx))
-				flags.classpath = append(flags.classpath, depHeaderJars...)
-				transitiveClasspathHeaderJars = append(transitiveClasspathHeaderJars,
-					android.NewDepSet(android.PREORDER, depHeaderJars, nil))
+				sdkInfo, _ := android.OtherModuleProvider(ctx, module, SdkLibraryInfoProvider)
+				generatingLibsString := android.PrettyConcat(
+					getGeneratingLibs(ctx, j.SdkVersion(ctx), module.Name(), sdkInfo), true, "or")
+				ctx.ModuleErrorf("cannot depend directly on java_sdk_library %q; try depending on %s instead", module.Name(), generatingLibsString)
 			}
 		}