Declare a public field for new Japanese Era Reiwa

Integrate OpenJDK commit for new Japanese Era name:

 * 8174268: Declare a public field in JapaneseEra for the era starting May 2019
   http://hg.openjdk.java.net/jdk/jdk/rev/6a4abdb6749c

Bug: 149437171
Test: CtsLibcoreTestCases CtsLibcoreOjTestCases
Merged-In: I1cbc9a12744d3cea214ee3b4a2872a9ad144e147
Change-Id: I1cbc9a12744d3cea214ee3b4a2872a9ad144e147
diff --git a/api/current.txt b/api/current.txt
index 80a7bb4..0f56af0 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -69783,6 +69783,7 @@
     method public static java.time.chrono.JapaneseEra[] values();
     field public static final java.time.chrono.JapaneseEra HEISEI;
     field public static final java.time.chrono.JapaneseEra MEIJI;
+    field public static final java.time.chrono.JapaneseEra REIWA;
     field public static final java.time.chrono.JapaneseEra SHOWA;
     field public static final java.time.chrono.JapaneseEra TAISHO;
   }
diff --git a/api/lint-baseline.txt b/api/lint-baseline.txt
index 5c31f41..b14a12f 100644
--- a/api/lint-baseline.txt
+++ b/api/lint-baseline.txt
@@ -537,6 +537,9 @@
     
 MissingNullability: android.icu.util.VersionInfo#UNICODE_13_0:
     Missing nullability on field `UNICODE_13_0` in class `class android.icu.util.VersionInfo`
+    
+MissingNullability: java.time.chrono.JapaneseEra#REIWA:
+    Missing nullability on field `REIWA` in class `class java.time.chrono.JapaneseEra`
 
 
 RequiresPermission: android.accounts.AccountManager#getAccountsByTypeAndFeatures(String, String[], android.accounts.AccountManagerCallback<android.accounts.Account[]>, android.os.Handler):