Update metadata.avdl
Update metadata.avdl

Re. comments from @diekans changing ```recordCreated``` => ```recordCreateTime``` and ```recordUpdated``` => ```recordUpdateTime```.
dglazer/schemas,hjellinek/schemas,ga4gh/schemas,laserson/schemas,benedictpaten/schemas,delagoya/schemas,diekhans/ga4gh-schemas,adamnovak/schemas,sarahhunt/schemas,hjellinek/schemas,saupchurch/schemas,adamnovak/schemas,benedictpaten/schemas,laserson/schemas,sarahhunt/schemas,ga4gh/ga4gh-schemas,lh3/schemas,delagoya/schemas,hjellinek/jeltje-schemas-sphinx,dnanexus-rnd/schemas,Jeltje/ga4gh-schemas,nlwashington/schemas,nlwashington/schemas,kellrott/schemas,dnanexus-rnd/schemas,pcingola/schemas,dcolligan/schemas,heuermh/ga4gh-schemas,macieksmuga/schemas,diekhans/ga4gh-schemas,Jeltje/ga4gh-schemas,buske/schemas,lh3/schemas,buske/schemas,kellrott/schemas