Add external storage permissions and fix verification

Change-Id: Ifac1992756521ec144d2dcfc507fc101be2b8e63

Author: bmeike

lib/src/main/AndroidManifest.xml

@@ -21,5 +21,8 @@ limitations under the License.
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
 
+    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
+    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
+
     <application android:label="@string/app_name"></application>
 </manifest>

lib/src/main/java/com/couchbase/lite/CouchbaseLite.java

@@ -142,9 +142,12 @@ static Map<String, String> loadErrorMessages(@NonNull Context ctxt) {
     private static String verifyDir(@Nullable File dir) {
         if (dir == null) { return null; }
 
-        final String path = dir.getAbsolutePath();
-        if ((dir.exists() && dir.isDirectory()) || dir.mkdirs()) { return path; }
+        IOException err = null;
+        try {
+            if ((dir.exists() && dir.isDirectory()) || dir.mkdirs()) { return dir.getCanonicalPath(); }
+        }
+        catch (IOException e) { err = e; }
 
-        throw new IllegalStateException("Cannot create or access directory at " + path);
+        throw new IllegalStateException("Cannot create or access directory at " + dir, err);
     }
 }

lib/src/main/java/com/couchbase/lite/internal/AndroidExecutionService.java

@@ -100,7 +100,7 @@ public Cancellable postDelayedOnExecutor(long delayMs, @NonNull Executor executo
                 Log.w(LogDomain.DATABASE, "Scheduled on closed executor: " + task + ", " + executor);
             }
             catch (RejectedExecutionException e) {
-                dumpServiceState(executor, "after: " + delayMs, e);
+                if (!throttled()) { dumpServiceState(executor, "after: " + delayMs, e); }
             }
         };