Add configurable behavior of the back button

This PR allows users to change how the back button functions. Closes #2196

Possible choices are following:

 - **Default** - back button functions how it currently functions (closes the app if there is nowhere to go back to)

 - **Open navigation drawer** - back button always opens the navigation drawer instead of closing the app

 - **Double tap to exit** - like default, but requires two taps to close the app

 - **Confirm to exit** - like default, but prompts user if they really want to exit

1 files changed, 9 insertions, 0 deletions

diff --git a/core/src/main/res/values/strings.xml b/core/src/main/res/values/strings.xml
index ad91ecc76..fd5535462 100644
--- a/core/src/main/res/values/strings.xml
+++ b/core/src/main/res/values/strings.xml
@@ -470,6 +470,15 @@
     <string name="pref_videoBehavior_sum">Behavior when leaving video playback</string>
     <string name="stop_playback">Stop playback</string>
     <string name="continue_playback">Continue audio playback</string>
+    <string name="behavior">Behavior</string>
+    <string name="pref_back_button_behavior_title">Back button behavior</string>
+    <string name="pref_back_button_behavior_sum">Change behavior of the back button.</string>
+    <string name="back_button_default">Default</string>
+    <string name="back_button_open_drawer">Open navigation drawer</string>
+    <string name="back_button_double_tap">Double tap to exit</string>
+    <string name="back_button_show_prompt">Confirm to exit</string>
+    <string name="close_prompt">Are you sure you want to close AntennaPod?</string>
+    <string name="double_tap_toast">Tap back button again to exit</string>
 
     <!-- Auto-Flattr dialog -->
     <string name="auto_flattr_enable">Enable automatic flattring</string>