Update default versions v2-0-test in the 2.0 branch (#12962)

Dockerfile

@@ -160,7 +160,7 @@ ARG AIRFLOW_EXTRAS
 ARG ADDITIONAL_AIRFLOW_EXTRAS=""
 ENV AIRFLOW_EXTRAS=${AIRFLOW_EXTRAS}${ADDITIONAL_AIRFLOW_EXTRAS:+,}${ADDITIONAL_AIRFLOW_EXTRAS}
 
-ARG AIRFLOW_CONSTRAINTS_REFERENCE="constraints-master"
+ARG AIRFLOW_CONSTRAINTS_REFERENCE="constraints-2-0"
 ARG AIRFLOW_CONSTRAINTS_LOCATION="https://raw.githubusercontent.com/apache/airflow/${AIRFLOW_CONSTRAINTS_REFERENCE}/constraints-${PYTHON_MAJOR_MINOR_VERSION}.txt"
 ENV AIRFLOW_CONSTRAINTS_LOCATION=${AIRFLOW_CONSTRAINTS_LOCATION}
 

scripts/ci/libraries/_initialization.sh

@@ -199,8 +199,8 @@ function initialization::initialize_base_variables() {
 # Determine current branch
 function initialization::initialize_branch_variables() {
     # Default branch used - this will be different in different branches
-    export DEFAULT_BRANCH=${DEFAULT_BRANCH="master"}
-    export DEFAULT_CONSTRAINTS_BRANCH=${DEFAULT_CONSTRAINTS_BRANCH="constraints-master"}
+    export DEFAULT_BRANCH=${DEFAULT_BRANCH="v2-0-test"}
+    export DEFAULT_CONSTRAINTS_BRANCH=${DEFAULT_CONSTRAINTS_BRANCH="constraints-2-0"}
     readonly DEFAULT_BRANCH
     readonly DEFAULT_CONSTRAINTS_BRANCH