when retrying to get SQLite db, throw first exception

* When we retry getting the SQLite database up to 5 times, let's throw the first `SQLiteCantOpenDatabaseException` or `SQLiteDatabaseLockedException` encountered instead of the last one.

* This may help give insight into a root cause for crashes seen about:
- Cannot open database
- OneSignal.db doesn't exist
- unknown error (code 14): Could not open database

Author: nan-li

OneSignalSDK/onesignal/src/main/java/com/onesignal/OneSignalDbHelper.java

@@ -168,13 +168,19 @@ private SQLiteDatabase getSQLiteDatabase() {
     */
    private SQLiteDatabase getSQLiteDatabaseWithRetries() {
       synchronized (LOCK) {
+         // Throw the first exception as this may give more insight into the root cause of issue:
+         // https://github.com/OneSignal/OneSignal-Android-SDK/issues/1432
+         SQLiteException firstSQLiteException = null;
          int count = 0;
          while (true) {
             try {
                return getSQLiteDatabase();
             } catch (SQLiteCantOpenDatabaseException | SQLiteDatabaseLockedException e) {
+               if (firstSQLiteException == null) {
+                  firstSQLiteException = e;
+               }
                if (++count >= DB_OPEN_RETRY_MAX)
-                  throw e;
+                  throw firstSQLiteException;
                SystemClock.sleep(count * DB_OPEN_RETRY_BACKOFF);
             }
          }