chore: [SDK-5280] raise minimum iOS version to 15 (#899)

Author: nan-li

README.md

@@ -52,7 +52,7 @@ And via many additional platforms. [Check them all out](https://documentation.on
 - iOS Builds: CocoaPods 1.11.3 or newer
 - In order to test push notifications you will need
   - An Android 7 or newer device or emulator with "Google Play Store (Services)" installed
-  - An iOS 12 or newer device (iPhone, iPad, or iPod Touch)
+  - An iOS 15 or newer device (iPhone, iPad, or iPod Touch)
 
 ### Push Notification Credentials
 You must generate the appropriate credentials for the platform(s) you are releasing on:

com.onesignal.unity.ios/Editor/BuildPostProcessor.cs

@@ -219,7 +219,7 @@ private void AddNotificationServiceExtension()
 
             // Makes it so that the extension target is Universal (not just iPhone)
             _project.SetBuildProperty(extensionGuid, "TARGETED_DEVICE_FAMILY", "1,2");
-            _project.SetBuildProperty(extensionGuid, "IPHONEOS_DEPLOYMENT_TARGET", "12.0");
+            _project.SetBuildProperty(extensionGuid, "IPHONEOS_DEPLOYMENT_TARGET", "15.0");
             _project.SetBuildProperty(extensionGuid, "SWIFT_VERSION", "5.0");
             _project.SetBuildProperty(
                 extensionGuid,

examples/demo-no-location/run-ios.sh

@@ -104,7 +104,7 @@ onesignal_version = next(
 lines = [
     "source 'https://cdn.cocoapods.org/'",
     "install! 'cocoapods', :disable_input_output_paths => true",
-    "platform :ios, '13.0'",
+    "platform :ios, '15.0'",
     "use_frameworks! :linkage => :static",
     "",
 ]

examples/demo/Assets/OneSignal/README.md

@@ -37,7 +37,7 @@ And via many additional platforms. [Check them all out](https://documentation.on
 - iOS Builds: CocoaPods 1.11.3 or newer
 - In order to test push notifications you will need
   - An Android 7 or newer device or emulator with "Google Play Store (Services)" installed
-  - An iOS 12 or newer device (iPhone, iPad, or iPod Touch)
+  - An iOS 15 or newer device (iPhone, iPad, or iPod Touch)
 
 ### Push Notification Credentials
 You must generate the appropriate credentials for the platform(s) you are releasing on: