Filter out hidden indices when checking cluster health (7.x)

[nagyo]

No description provided.

[apeteri]

The corresponding PR on 8.x that includes a change compatible with the addition of lenientExpand done here is #1053:

snow-owl/commons/com.b2international.index/src/com/b2international/index/es/client/EsClientBase.java

Lines 63 to 72 in 8d86b1e

	// Equivalent to org.elasticsearch.action.support.IndicesOptions.lenientExpand() with ignore_throttled set to true
	private static final IndicesOptions DEFAULT_INDICES_OPTIONS = new IndicesOptions(
	EnumSet.of(
	Option.ALLOW_NO_INDICES,
	Option.IGNORE_UNAVAILABLE,
	// this has to be set to avoid deprecation warnings in the log, see org.elasticsearch.client.RequestConverters.Params.withIndicesOptions(IndicesOptions)
	Option.IGNORE_THROTTLED
	),
	EnumSet.of(WildcardStates.OPEN, WildcardStates.CLOSED)
	);