fix: fix the theme when the app is with .scss styles

Author: Fatme

src/styling/_scss-files/_app-common.scss

@@ -1,2 +1,21 @@
+@import "~@nativescript/theme/core";
+@import "~@nativescript/theme/blue";
+
 // Place any CSS rules you want to apply on both iOS and Android here.
 // This is where the vast majority of your CSS code goes.
+
+// Font icon class
+.fab {
+    font-family: "Font Awesome 5 Brands", "fa-brands-400";
+    font-weight: 400;
+}
+
+.fas {
+    font-family: "Font Awesome 5 Free", "fa-solid-900";
+    font-weight: 900;
+}
+
+.far {
+    font-family: "Font Awesome 5 Free", "fa-regular-400";
+    font-weight: 400;
+}