android: Convert StringSetting to Kotlin

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/model/StringSetting.java

@@ -1,23 +0,0 @@
-package org.yuzu.yuzu_emu.features.settings.model;
-
-public final class StringSetting extends Setting {
-    private String mValue;
-
-    public StringSetting(String key, String section, String value) {
-        super(key, section);
-        mValue = value;
-    }
-
-    public String getValue() {
-        return mValue;
-    }
-
-    public void setValue(String value) {
-        mValue = value;
-    }
-
-    @Override
-    public String getValueAsString() {
-        return mValue;
-    }
-}

src/android/app/src/main/java/org/yuzu/yuzu_emu/features/settings/model/StringSetting.kt

@@ -0,0 +1,9 @@
+package org.yuzu.yuzu_emu.features.settings.model
+
+class StringSetting(
+    key: String,
+    section: String,
+    var value: String
+) : Setting(key, section) {
+    override var valueAsString = value
+}