android: Remove unused dimensions files

src/android/app/src/main/res/values-w1050dp/dimens.xml

@@ -1,5 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<resources>
-    <!-- Example customization of dimensions originally defined in res/values/dimens.xml
-         (such as screen margins) for screens with more than 1024dp of available width.  -->
-</resources>

src/android/app/src/main/res/values-w820dp/dimens.xml

@@ -1,4 +0,0 @@
-<resources>
-    <!-- Example customization of dimensions originally defined in res/values/dimens.xml
-         (such as screen margins) for screens with more than 820dp of available width.  -->
-</resources>