Add API for changing set exact setting

Author: aurimasc

com.unity.mobile.notifications/Editor/NotificationSettings.cs

@@ -99,6 +99,21 @@ public static string CustomActivityString
                 }
             }
 
+            /// <summary>
+            /// A set of flags indicating whether to use exact scheduling and add supporting permissions.
+            /// </summary>
+            public static AndroidExactSchedulingOption ExactSchedulingOption
+            {
+                get
+                {
+                    return GetSettingValue<AndroidExactSchedulingOption>(BuildTargetGroup.Android, EXACT_ALARM);
+                }
+                set
+                {
+                    SetSettingValue<AndroidExactSchedulingOption>(BuildTargetGroup.Android, EXACT_ALARM, value);
+                }
+            }
+
             /// <summary>
             /// Add image to notification settings.
             /// </summary>