android: Support changing multiple settings at once

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/ui/SettingsFragmentPresenter.kt

@@ -42,7 +42,7 @@ class SettingsFragmentPresenter(private val fragmentView: SettingsFragmentView)
     }
 
     fun putSetting(setting: AbstractSetting) {
-        if (setting.section == null) {
+        if (setting.section == null || setting.key == null) {
             return
         }
 

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/utils/SettingsFile.kt

@@ -244,5 +244,21 @@ object SettingsFile {
             val setting = settings[key]
             parser.put(header, setting!!.key, setting.valueAsString)
         }
+
+        BooleanSetting.values().forEach {
+            if (!keySet.contains(it.key)) {
+                parser.put(header, it.key, it.valueAsString)
+            }
+        }
+        IntSetting.values().forEach {
+            if (!keySet.contains(it.key)) {
+                parser.put(header, it.key, it.valueAsString)
+            }
+        }
+        StringSetting.values().forEach {
+            if (!keySet.contains(it.key)) {
+                parser.put(header, it.key, it.valueAsString)
+            }
+        }
     }
 }