When a shard becomes search active then trigger a refresh instead of waiting for the next scheduled refresh.
The `IndexShard#awaitShardSearchActive(...)` method registers a refresh listener and then often waits for the refresh scheduler to trigger a refresh. By default this is one second. In order to avoid increasing the query time of the Search API, the mentioned method should trigger a refresh instead for waiting it to happen.

As part of this change we also need to disable the refresh scheduler completely. Otherwise we run at risk of running two refreshes next after each other. One triggered from making shard search active and one from the refresh scheduler.  



server/src/main/java/org/elasticsearch/index/shard/IndexShard.java
}
    /**
     * Acquires a lock on the translog files and Lucene soft-deleted documents to prevent them from being trimmed
     */
    public Closeable acquireHistoryRetentionLock() {
        return getEngine().acquireHistoryRetentionLock();
    }
    /**
     * Checks if we have a completed history of operations since the given starting seqno (inclusive).
     * This method should be called after acquiring the retention lock; See {@link #acquireHistoryRetentionLock()}
     */
    public boolean hasCompleteHistoryOperations(String reason, long startingSeqNo) {
        return getEngine().hasCompleteOperationHistory(reason, startingSeqNo);
    }
    /**
     * Gets the minimum retained sequence number for this engine.
     *
     * @return the minimum retained sequence number
     */
    public long getMinRetainedSeqNo() {
        return getEngine().getMinRetainedSeqNo();
    }
    /**
     * Counts the number of operations in the range of the given sequence numbers.
     *
     * @param source    the source of the request
     * @param fromSeqNo the start sequence number (inclusive)
     * @param toSeqNo   the end sequence number (inclusive)
     * @see #newChangesSnapshot(String, long, long, boolean, boolean, boolean)
     */