fix: unify Title Case in English strings for Weblate consistency [skip ci]

Author: inventory69

android/app/src/main/res/values/strings.xml

@@ -10,7 +10,7 @@
     <!-- ============================= -->
     <string name="main_title">Simple Notes</string>
     <string name="no_notes_yet">No notes yet.\nTap + to create one.</string>
-    <string name="add_note">Add note</string>
+    <string name="add_note">Add Note</string>
     <string name="sync">Sync</string>
     <string name="settings">Settings</string>
     <string name="action_sync">Sync</string>
@@ -30,8 +30,8 @@
     <!-- ============================= -->
     <!-- FAB MENU                      -->
     <!-- ============================= -->
-    <string name="fab_new_note">New note</string>
-    <string name="fab_text_note">Text note</string>
+    <string name="fab_new_note">New Note</string>
+    <string name="fab_text_note">Text Note</string>
     <string name="fab_checklist">Checklist</string>
     <string name="create_text_note">Note</string>
     <string name="create_checklist">List</string>