Bug 8885: Fix DistributedShardedDOMDataTree initialization

Bug 8885: Fix DistributedShardedDOMDataTree initialization

DistributedShardedDOMDataTree initialization expects the prefix
configuration shard to be present and ready with leader however
the latter isn't the case when the static module-shards is
bootstrapped without the local member so it can be dynamically
joined into an existing cluster. So I modified the ConfigShardLookupTask
to elide the ConfigShardReadinessTask.

Once past that, creation of the prefix-based default shard is attempted
as there isn't a local module-based shard however this fails b/c the
local prefix configuration shard is not connected to a leader. To alleviate
this I just commented out the code to create the shard. Since the default
shard configuration is present in the out-of-box modules.conf and is
expected to be present, we can assume at this point that the local member
isn't in the replica list with the intention of dynamically joining it to
an existing cluster, at which time the shard will be created.

These changes at least fix the regression with the boostrapping scenario.
We can revisit this iniialization later w.r.t. prefix-based shards.

Change-Id: I1faf531f4c79914d45203ee132dd4e65ad2f18ba
Signed-off-by: Tom Pantelis <tompantelis@gmail.com>