[split] util: release version 6.3.7
[split] util: release version 6.3.7

RB_ID=159374
TBR=true
NO-QUEUE=true

twitter/ostrich,yonglehou/ostrich,travisbrown/ostrich,hydro2k/ostrich,yeghishe/ostrich,yonglehou/ostrich,travisbrown/ostrich,cogitate/twitter-ostrich-uuid,hydro2k/ostrich,twitter/ostrich,yonglehou/ostrich,twitter/ostrich,yeghishe/ostrich,twitter/ostrich,travisbrown/ostrich,twitter/ostrich,cogitate/twitter-ostrich-uuid,yonglehou/ostrich,cogitate/twitter-ostrich-uuid,yonglehou/ostrich,yeghishe/ostrich,hydro2k/ostrich,yeghishe/ostrich,hydro2k/ostrich,cogitate/twitter-ostrich-uuid,yeghishe/ostrich,travisbrown/ostrich,cogitate/twitter-ostrich-uuid,hydro2k/ostrich,travisbrown/ostrich