[Android] Avoid using OffsetDateTime on APIs 25 and lower

src/tasks/AndroidAppBuilder/Templates/MonoRunner.java

@@ -24,6 +24,7 @@
 import java.io.OutputStream;
 import java.io.BufferedInputStream;
 import java.util.ArrayList;
+import java.util.Calendar;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipInputStream;
 import java.time.OffsetDateTime;
@@ -90,7 +91,7 @@ public static int initialize(String entryPointLibName, String[] args, Context co
         unzipAssets(context, filesDir, "assets.zip");
 
         Log.i("DOTNET", "MonoRunner initialize,, entryPointLibName=" + entryPointLibName);
-        int localDateTimeOffset = OffsetDateTime.now().getOffset().getTotalSeconds();
+        int localDateTimeOffset = getLocalDateTimeOffset();
         return initRuntime(filesDir, cacheDir, testResultsDir, entryPointLibName, args, localDateTimeOffset);
     }
 
@@ -152,6 +153,15 @@ static void unzipAssets(Context context, String toPath, String zipName) {
         }
     }
 
+    static int getLocalDateTimeOffset() {
+        if (android.os.Build.VERSION.SDK_INT >= 26) {
+            return OffsetDateTime.now().getOffset().getTotalSeconds();
+        } else {
+            int offsetInMillis = Calendar.getInstance().getTimeZone().getRawOffset();
+            return offsetInMillis / 1000;
+        }
+    }
+
     static native int initRuntime(String libsDir, String cacheDir, String testResultsDir, String entryPointLibName, String[] args, int local_date_time_offset);
 
     static native int setEnv(String key, String value);