copy JNI from AAR files to android_app APK

JNI libs present in AAR files are ignored in the build. If those
libraries are necessary, they must be manually extracted and a
prebuilt_cc_library module must be created for them. Instead, we can
extract these libraries and copy them to an output APK as part of the build.

Bug: 228848794
Test: created android_app that depends on an android_library_import with
  JNI embedded, and verified that .so libs are present in APK
Test: created android_app that depends on an android_library which
  depends on android_library_import with JNI embedded, and verified
  that .so libs are present in APK
Test: verified that multiple .so's from a single architecture are copied
  to APK
Test: verified that the absence of a jni/<arch> folder or files in the
  folder will cause the Ninja action to error
Change-Id: I242a862d7bd881f7a4a8c23493924d8fe441ea25

java/aar_test.go

@@ -0,0 +1,83 @@
+// Copyright 2022 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package java
+
+import (
+	"android/soong/android"
+	"testing"
+)
+
+func TestAarImportProducesJniPackages(t *testing.T) {
+	ctx := android.GroupFixturePreparers(
+		PrepareForTestWithJavaDefaultModules,
+	).RunTestWithBp(t, `
+		android_library_import {
+			name: "aar-no-jni",
+			aars: ["aary.aar"],
+		}
+		android_library_import {
+			name: "aar-jni",
+			aars: ["aary.aar"],
+			extract_jni: true,
+		}`)
+
+	testCases := []struct {
+		name       string
+		hasPackage bool
+	}{
+		{
+			name:       "aar-no-jni",
+			hasPackage: false,
+		},
+		{
+			name:       "aar-jni",
+			hasPackage: true,
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			appMod := ctx.Module(tc.name, "android_common")
+			appTestMod := ctx.ModuleForTests(tc.name, "android_common")
+
+			info, ok := ctx.ModuleProvider(appMod, JniPackageProvider).(JniPackageInfo)
+			if !ok {
+				t.Errorf("expected android_library_import to have JniPackageProvider")
+			}
+
+			if !tc.hasPackage {
+				if len(info.JniPackages) != 0 {
+					t.Errorf("expected JniPackages to be empty, but got %v", info.JniPackages)
+				}
+				outputFile := "arm64-v8a_jni.zip"
+				jniOutputLibZip := appTestMod.MaybeOutput(outputFile)
+				if jniOutputLibZip.Rule != nil {
+					t.Errorf("did not expect an output file, but found %v", outputFile)
+				}
+				return
+			}
+
+			if len(info.JniPackages) != 1 {
+				t.Errorf("expected a single JniPackage, but got %v", info.JniPackages)
+			}
+
+			outputFile := info.JniPackages[0].String()
+			jniOutputLibZip := appTestMod.Output(outputFile)
+			if jniOutputLibZip.Rule == nil {
+				t.Errorf("did not find output file %v", outputFile)
+			}
+		})
+	}
+}