Added preference to change password

Closes #20

app/src/main/java/me/impy/aegis/ui/PreferencesFragment.java

@@ -162,6 +162,15 @@ public class PreferencesFragment extends PreferenceFragmentCompat implements Pas
                 return false;
             }
         });
+
+        Preference setPasswordPreference = findPreference("pref_password");
+        setPasswordPreference.setOnPreferenceClickListener(preference -> {
+            PasswordDialogFragment dialog = new PasswordDialogFragment();
+            // TODO: find a less ugly way to obtain the fragment manager
+            dialog.show(getActivity().getSupportFragmentManager(), null);
+            return false;
+        });
+
         _slotsPreference = findPreference("pref_slots");
         _slotsPreference.setOnPreferenceClickListener(new Preference.OnPreferenceClickListener() {
             @Override

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

@@ -27,6 +27,8 @@
     <string name="pref_secure_screen_summary">Block screenshots and other attempts to capture the screen within the app</string>
     <string name="pref_encryption_title">Encryption</string>
     <string name="pref_encryption_summary">Encrypt the database and unlock it with a password or fingerprint</string>
+    <string name="pref_set_password_title">Change password</string>
+    <string name="pref_set_password_summary">Set a new password which you will need to unlock your vault</string>
 
     <string name="fingerprint_hint">Touch sensor</string>
     <string name="fingerprint_not_recognized">Fingerprint not recognized. Try again.</string>

app/src/main/res/xml/preferences.xml

@@ -45,6 +45,14 @@
             android:summary="@string/pref_encryption_summary"
             android:persistent="false"
             app:iconSpaceReserved="false"/>
+
+        <Preference
+            android:key="pref_password"
+            android:title="@string/pref_set_password_title"
+            android:summary="@string/pref_set_password_summary"
+            android:dependency="pref_encryption"
+            app:iconSpaceReserved="false"/>
+
         <Preference
             android:key="pref_slots"
             android:title="@string/pref_slots_title"