Turn splash screen duration into a resource variable

so screenshot tests can define a different duration

briar-android/src/main/java/org/briarproject/briar/android/splash/SplashScreenActivity.java

@@ -61,6 +61,8 @@ public class SplashScreenActivity extends BaseActivity {
 			startNextActivity(ENTRY_ACTIVITY);
 			finish();
 		} else {
+			int duration =
+					getResources().getInteger(R.integer.splashScreenDuration);
 			new Handler().postDelayed(() -> {
 				if (currentTimeMillis() >= EXPIRY_DATE) {
 					LOG.info("Expired");
@@ -69,7 +71,7 @@ public class SplashScreenActivity extends BaseActivity {
 					startNextActivity(ENTRY_ACTIVITY);
 				}
 				supportFinishAfterTransition();
-			}, 500);
+			}, duration);
 		}
 	}
 

briar-android/src/main/res/values/attrs.xml

@@ -3,6 +3,8 @@
 
 	<integer name="animationSpeed">@android:integer/config_mediumAnimTime</integer>
 
+	<integer name="splashScreenDuration">500</integer>
+
 	<declare-styleable name="BriarRecyclerView">
 		<attr name="scrollToEnd" format="boolean" />
 		<attr name="emptyImage" format="integer" />

briar-android/src/screenshotDebug/res/values/attrs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+
+	<integer name="splashScreenDuration">7500</integer>
+
+</resources>