[Breakpad] Add get_context_unittest to breakpad_unittests for Android.

BUG=354405,346626

Review URL: https://codereview.chromium.org/229653003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@262820 0039d316-1c4b-4281-b951-d872f2087c98

breakpad/breakpad.gyp

@@ -614,6 +614,9 @@
               'include_dirs': [
                 'src/common/android/include',
               ],
+              'sources': [
+                'src/common/android/breakpad_getcontext_unittest.cc',
+              ],
             }],
           ],
         },