add constant to c# code

Author: dbasedow

windows/CodePushNativeModule.cs

@@ -40,6 +40,7 @@ public override IReadOnlyDictionary<string, object> Constants
                     { "codePushInstallModeImmediate", InstallMode.Immediate },
                     { "codePushInstallModeOnNextResume", InstallMode.OnNextResume },
                     { "codePushInstallModeOnNextRestart", InstallMode.OnNextRestart },
+                    { "codePushInstallModeOnNextRestartOpportunity", InstallMode.OnNextRestartOpportunity },
                     { "codePushUpdateStateRunning", UpdateState.Running },
                     { "codePushUpdateStatePending", UpdateState.Pending },
                     { "codePushUpdateStateLatest", UpdateState.Lastest },

windows/InstallMode.cs

@@ -4,6 +4,7 @@ enum InstallMode
     {
         Immediate,
         OnNextRestart,
-        OnNextResume
+        OnNextResume,
+        OnNextRestartOpportunity
     }
 }