harmonize --current-branch short option across subcommands

We're inconsistent with the short option for this flag:
* gitc-init: <none as -c is already used>
* info:      -b
* init:      -c
* overview:  -b
* sync:      -c
* upload:   --cbr

Since info & overview are not as heavily used as the others, switch
them from -b to -c.  We leave -b in as a hidden alias for now.

Similarly, switch upload from --cbr to just -c.  A lot of people
use --cbr, so we leave this as a hidden alias for now too.

Ideally gitc-init wouldn't use -c, but that ship has sailed, and
we're more likely to deprecate gitc entirely at this point.

This provides a consistent set of options across subcommands.

Bug: https://crbug.com/gerrit/12401
Change-Id: Iec249729223866fe1ea0ebabed12ca851cc38b35
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/304902
Reviewed-by: Raman Tenneti <rtenneti@google.com>
Tested-by: Mike Frysinger <vapier@google.com>

subcmds/upload.py

@@ -14,6 +14,7 @@
 
 import copy
 import functools
+import optparse
 import re
 import sys
 
@@ -170,9 +171,13 @@ Gerrit Code Review:  https://www.gerritcodereview.com/
     p.add_option('--br', '--branch',
                  type='string', action='store', dest='branch',
                  help='(Local) branch to upload.')
-    p.add_option('--cbr', '--current-branch',
+    p.add_option('-c', '--current-branch',
                  dest='current_branch', action='store_true',
                  help='Upload current git branch.')
+    # Turn this into a warning & remove this someday.
+    p.add_option('--cbr',
+                 dest='current_branch', action='store_true',
+                 help=optparse.SUPPRESS_HELP)
     p.add_option('--ne', '--no-emails',
                  action='store_false', dest='notify', default=True,
                  help='If specified, do not send emails on upload.')