Address warnings in Dockerfiles

[emerkle826]

Recent updates to Docker have started showing some warnings with our current set of Dockerfiles, similar to this:

 10 warnings found (use --debug to expand):
 - ConsistentInstructionCasing: Command 'copy' should match the case of the command majority (uppercase) (line 99)
 - FromAsCasing: 'as' and 'FROM' keywords' casing do not match (line 8)
 - FromAsCasing: 'as' and 'FROM' keywords' casing do not match (line 60)
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 12)
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 13)
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 71)
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 72)
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 73)
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 114)
 - LegacyKeyValueFormat: "ENV key=value" should be used instead of legacy "ENV key value" format (line 115)

They are just warnings, and the images build correctly, but at some point they should be addressed.