chore: Bump version to 1.6

Updates the application version:
*   `versionCode` from 6 to 7
*   `versionName` from "1.5" to "1.6"

Author: oftx

app/build.gradle.kts

@@ -13,8 +13,8 @@ android {
         applicationId = "github.oftx.smsforwarder"
         minSdk = 26
         targetSdk = 36
-        versionCode = 6
-        versionName = "1.5"
+        versionCode = 7
+        versionName = "1.6"
 
         testInstrumentationRunner = "androidx.test.runner.AndroidJUnitRunner"
     }