Description of problem:

When we do not use "spec.source.git.revision" ,  it automatically does a  shallow git clone which is same behaviour with buildconfig.  But when we   specify "spec.source.git.revision", it does a full git clone.

Workaround: None

Prerequisites (if any, like setup, operators/versions):

• Builds for OpenShift 1.3

Steps to Reproduce

1. Create a `Build` as follows:
   1. Use the `buildah` strategy to create a build with a Dockerfile at the source root.
   2. In the source for the build, use a Dockerfile that prints the size of the .git directory:

         FROM registry.access.redhat.com/ubi9/ubi:latest
         RUN mkdir -p /opt/app-root
         WORKDIR /opt/app-root
         COPY . .
         RUN ls -al .git
       

   3. Ensure the build source from git using a specific revision. This could be a branch, tag, or commit sha.
2. Start a `BuildRun` from said build, using the `shp` command line (`shp build run ...`)

Actual results:

Git source contains the full history

Expected results:

Git has a shallow clone, which does not contain the full history.

Reproducibility (Always/Intermittent/Only Once):

Always

Acceptance criteria: 

Cloning with our without the revision specified produces the same behavior - shallow clone by default.

Definition of Done:

Build Details:

Additional info (Such as Logs, Screenshots, etc):