Misc PGP v2 fixes (#1784)

* Don't throw in PGPKeyImportActivity when no file is selected

* PGPSettings: mark import option as dependent on V2 backend pref

app/src/main/java/dev/msfjarvis/aps/ui/pgp/PGPKeyImportActivity.kt

@@ -29,7 +29,7 @@ class PGPKeyImportActivity : AppCompatActivity() {
     registerForActivityResult(OpenDocument()) { uri ->
       runCatching {
           if (uri == null) {
-            throw IllegalStateException("Selected URI was null")
+            return@runCatching null
           }
           val keyInputStream =
             contentResolver.openInputStream(uri)
@@ -41,13 +41,14 @@ class PGPKeyImportActivity : AppCompatActivity() {
         }
         .mapBoth(
           { key ->
-            require(key != null) { "Key cannot be null here" }
+            if (key != null) {
               MaterialAlertDialogBuilder(this)
                 .setTitle(getString(R.string.pgp_key_import_succeeded))
                 .setMessage(getString(R.string.pgp_key_import_succeeded_message, tryGetId(key)))
                 .setPositiveButton(android.R.string.ok) { _, _ -> finish() }
                 .setOnCancelListener { finish() }
                 .show()
+            }
           },
           { throwable ->
             MaterialAlertDialogBuilder(this)

app/src/main/java/dev/msfjarvis/aps/ui/settings/PGPSettings.kt

@@ -18,6 +18,7 @@ class PGPSettings(private val activity: FragmentActivity) : SettingsProvider {
 
   override fun provideSettings(builder: PreferenceScreen.Builder) {
     builder.apply {
+      val enablePGPainless =
         checkBox(Feature.EnablePGPainlessBackend.configKey) {
           title = "Enable new PGP backend"
           persistent = true
@@ -25,6 +26,7 @@ class PGPSettings(private val activity: FragmentActivity) : SettingsProvider {
       pref("_") {
         title = "Import PGP key"
         persistent = false
+        dependency = enablePGPainless.key
         onClick {
           activity.launchActivity(PGPKeyImportActivity::class.java)
           false