Clean up Dockerfile formatting

[lbussell]

We should ensure that our Dockerfiles adhere to consistent rules for formatting:

1. There should be 1 newline between instructions, and 2 newlines between stages. Example of where we use two lines between instructions:

   dotnet-docker/src/runtime-deps/7.0/cbl-mariner2.0-distroless/amd64/Dockerfile

   Lines 29 to 32 in c161034

   	&& tac $tmpManifestPath | gawk '!x[$1]++' | sort > /staging/var/lib/rpmmanifest/container-manifest-2
   	# Create a non-root user and group

2. Arguments to commands should be in alphabetical order. Example where they aren't:

   dotnet-docker/src/runtime-deps/7.0/cbl-mariner2.0-distroless/amd64/Dockerfile

   Lines 34 to 35 in c161034

   	--system \
   	--gid=101 \

3. The alphabetical order for arguments should also extend to things like lists of packages to install:

   dotnet-docker/src/runtime-deps/7.0/cbl-mariner2.0-distroless/amd64/Dockerfile

   Lines 15 to 20 in c161034

   	glibc \
   	krb5 \
   	libgcc \
   	libstdc++ \
   	openssl-libs \
   	zlib \

   
   (I didn't find a place where we violated this).

[mthalman]

Another point of consistency is the use of the = character for assigning option values. For example, these two are inconsistent:

dotnet-docker/src/runtime-deps/7.0/cbl-mariner2.0-distroless/amd64/Dockerfile

Line 35 in c161034

--gid=101 \

dotnet-docker/src/runtime-deps/7.0/cbl-mariner2.0-distroless/amd64/Dockerfile

Line 39 in c161034

--gid 101 \