Add flag to ignore unknown disk id warnings
Add flag to ignore unknown disk id warnings

In the future Impala will run on an implementation of HDFS that does not
fully implement the block location metadata API. The implementation only
has a single volume per node and does not provide volume information
along with the block location metadata. In that case, a new flag
-suppress_unknown_disk_id_warnings can be enabled to suppress related
messages. When the volume id is unknown, Impala will choose a volume at
random, but there is only one volume this is fine.

Change-Id: I9322c9453522eb27c49adc7365dd18f91142d9a3
Reviewed-on: http://gerrit.cloudera.org:8080/1615
Reviewed-by: Dan Hecht <20ebd99959f0f6e5dcb0fc319b4d8ef53a16b5fb@cloudera.com>
Tested-by: Internal Jenkins

kapilrastogi/Impala,kapilrastogi/Impala,kapilrastogi/Impala,kapilrastogi/Impala,kapilrastogi/Impala,kapilrastogi/Impala,kapilrastogi/Impala