Fix a couple camel case issues in strings

* This should finally cover all strings
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 5570635..4abfc61 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -28,7 +28,7 @@
     <string name="settings_backup_status_summary">Last backup: %1$s</string>
     <string name="settings_backup_exclude_apps">Exclude apps</string>
     <string name="settings_backup_now">Backup now</string>
-    <string name="settings_backup_recovery_code">Recovery Code</string>
+    <string name="settings_backup_recovery_code">Recovery code</string>
     <string name="settings_backup_recovery_code_summary">Verify existing code or generate a new one</string>
 
     <!-- Storage -->
@@ -154,6 +154,6 @@
     <string name="about_author">Written by: <a href="https://github.com/stevesoltys">Steve Soltys</a> and <a href="https://blog.grobox.de">Torsten Grote</a></string>
     <string name="about_design">Design by: <a href="https://www.glennsorrentino.com/">Glenn Sorrentino</a></string>
     <string name="about_sponsor">Sponsored by: <a href="https://www.calyxinstitute.org">Calyx Institute</a> for use in <a href="https://calyxos.org">CalyxOS</a></string>
-    <string name="about_source_code">Source Code: https://github.com/seedvault-app/seedvault</string>
+    <string name="about_source_code">Source code: https://github.com/seedvault-app/seedvault</string>
 
 </resources>