Prepare version codes for 0.14 release (#5624)

## Explanation
This PR introduces the necessary version code updates in order to
prepare for the upcoming 0.14 beta release of the app.

## Essential Checklist
- ~The PR title and explanation each start with "Fix #bugnum: " (If this
PR fixes part of an issue, prefix the title with "Fix part of #bugnum:
...".)~
- [x] Any changes to
[scripts/assets](https://github.com/oppia/oppia-android/tree/develop/scripts/assets)
files have their rationale included in the PR explanation.
- [x] The PR follows the [style
guide](https://github.com/oppia/oppia-android/wiki/Coding-style-guide).
- [x] The PR does not contain any unnecessary code changes from Android
Studio
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#undo-unnecessary-changes)).
- [x] The PR is made from a branch that's **not** called "develop" and
is up-to-date with "develop".
- [x] The PR is **assigned** to the appropriate reviewers
([reference](https://github.com/oppia/oppia-android/wiki/Guidance-on-submitting-a-PR#clarification-regarding-assignees-and-reviewers-section)).

## For UI-specific PRs only
N/A -- this is an infrastructure-only change (version code update).

Co-authored-by: Sean Lip <sean@seanlip.org>

Author: BenHenning

version.bzl

@@ -10,11 +10,11 @@ the app (that are potentially not broadly released yet).
 """
 
 MAJOR_VERSION = 0
-MINOR_VERSION = 13
+MINOR_VERSION = 14
 
-OPPIA_DEV_VERSION_CODE = 172
-OPPIA_DEV_KITKAT_VERSION_CODE = 171
-OPPIA_ALPHA_VERSION_CODE = 170
-OPPIA_ALPHA_KITKAT_VERSION_CODE = 169
-OPPIA_BETA_VERSION_CODE = 168
-OPPIA_GA_VERSION_CODE = 167
+OPPIA_DEV_VERSION_CODE = 178
+OPPIA_DEV_KITKAT_VERSION_CODE = 177
+OPPIA_ALPHA_VERSION_CODE = 176
+OPPIA_ALPHA_KITKAT_VERSION_CODE = 175
+OPPIA_BETA_VERSION_CODE = 174
+OPPIA_GA_VERSION_CODE = 173