Warn on backup creation for MIUI users

app/src/main/java/eu/kanade/tachiyomi/ui/setting/SettingsBackupController.kt

@@ -63,6 +63,11 @@ class SettingsBackupController : SettingsController() {
             summaryRes = R.string.pref_create_backup_summ
 
             onClick {
+                if (MiuiUtil.isMiui() && MiuiUtil.isMiuiOptimizationDisabled()) {
+                    context.toast(R.string.restore_miui_warning, Toast.LENGTH_LONG)
+                    return@onClick
+                }
+
                 if (!BackupCreateService.isRunning(context)) {
                     val ctrl = CreateBackupDialog()
                     ctrl.targetController = this@SettingsBackupController

app/src/main/res/values/strings.xml

@@ -422,7 +422,7 @@
     <string name="backup_choice">What do you want to backup?</string>
     <string name="creating_backup">Creating backup</string>
     <string name="creating_backup_error">Backup failed</string>
-    <string name="restore_miui_warning">MIUI Optimization must be enabled for restore to work correctly.</string>
+    <string name="restore_miui_warning">MIUI Optimization must be enabled for backup/restore to work correctly.</string>
     <string name="restore_in_progress">Restore is already in progress</string>
     <string name="restoring_backup">Restoring backup</string>
     <string name="restoring_backup_error">Restoring backup failed</string>