Add a new developer options screen for shared data.

Add a new Storage section in the developer options menu which has a
new Shared Data preference. This preference screen shows all shared data
blobs on the device. There is also a new screen for each data blob which
shows all of the packages which currently have a leases on it. This
screen also has a button to delete the shared data blob.

Bug: 150626561
Test: make RunSettingsRoboTests ROBOTEST_FILTER=SharedDataPreferenceControllerTest
Test: manual (visual)
Change-Id: Id84a33dc7eeac493b2f81d3996ad24ee70557a07

src/com/android/settings/development/storage/SharedDataUtils.java

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * 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 com.android.settings.development.storage;
+
+import android.icu.text.SimpleDateFormat;
+import android.icu.util.Calendar;
+import android.icu.util.TimeZone;
+
+import java.util.Locale;
+
+class SharedDataUtils {
+    static final String BLOB_KEY = "BLOB_KEY";
+
+    static final int LEASE_VIEW_REQUEST_CODE = 8108;
+    static final int LEASE_VIEW_RESULT_CODE_SUCCESS = 1;
+    static final int LEASE_VIEW_RESULT_CODE_FAILURE = -1;
+
+    private static final String BLOB_EXPIRY_PATTERN = "MMM dd, yyyy HH:mm:ss z";
+
+    private static final SimpleDateFormat FORMATTER = new SimpleDateFormat(BLOB_EXPIRY_PATTERN);
+    private static final Calendar CALENDAR = Calendar.getInstance(
+            TimeZone.getDefault(), Locale.getDefault());
+
+    static String formatTime(long millis) {
+        CALENDAR.setTimeInMillis(millis);
+        return FORMATTER.format(CALENDAR.getTime());
+    }
+}