Support date header and Recent in PhotosTabFragment

- Add DateHeaderHolder
- Update items for date header and recent
- Support ITEM_TYPE_DATE_HEADER in PhotosTabAdapter
- Add DateTimeUtils

Bug: 189732217
Test: Manual. videos on the bug.
Test: atest DateTimeUtilsTest
Test: atest ItemTest
Change-Id: I3e8b7582c743e12548fd44e71e8a5beb079f561f
Merged-In: I3e8b7582c743e12548fd44e71e8a5beb079f561f
(cherry picked from commit 1b6db2d497508fece1bfd4a194af7577bb8940ad)
diff --git a/res/values/styles_text.xml b/res/values/styles_text.xml
new file mode 100644
index 0000000..710631a
--- /dev/null
+++ b/res/values/styles_text.xml
@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2021 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.
+-->
+
+<resources xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <style name="PickerDateHeader" parent="@android:style/TextAppearance.Material.Title">
+        <item name="android:textColor">@color/picker_date_header_text_color</item>
+        <item name="android:textSize">16sp</item>
+    </style>
+
+</resources>