VERSION: bump to 5.0.2a1

Bump version after 5.0.1 release

bot:notacherrypick

Signed-off-by: Wenduo Wang <wenduwan@amazon.com>

VERSION

@@ -17,7 +17,7 @@
 
 major=5
 minor=0
-release=1
+release=2
 
 # MPI Standard Compliance Level
 mpi_standard_version=3
@@ -41,7 +41,7 @@ flex_min_version=2.5.4
 # requirement is that it must be entirely printable ASCII characters
 # and have no white space.
 
-greek=rc2
+greek=a1
 
 # If repo_rev is empty, then the repository version number will be
 # obtained during "make dist" via the "git describe --tags --always"