patch 8.2.0402: setting local instead of global flag

Problem:    Setting local instead of global flag.
Solution:   Prepend "g:" to "test_is_flaky".

src/testdir/screendump.vim

@@ -25,7 +25,7 @@ func VerifyScreenDump(buf, filename, options, ...)
   let testfile = 'failed/' . a:filename . '.dump'
 
   " Starting a terminal to make a screendump is always considered flaky.
-  let test_is_flaky = 1
+  let g:test_is_flaky = 1
 
   " Redraw to execute the code that updates the screen.  Otherwise we get the
   " text and attributes only from the internal buffer.

src/testdir/term_util.vim

@@ -94,7 +94,7 @@ func RunVimInTerminal(arguments, options)
   endtry
 
   " Starting a terminal to run Vim is always considered flaky.
-  let test_is_flaky = 1
+  let g:test_is_flaky = 1
 
   return buf
 endfunc
@@ -102,7 +102,7 @@ endfunc
 " Stop a Vim running in terminal buffer "buf".
 func StopVimInTerminal(buf)
   " Using a terminal to run Vim is always considered flaky.
-  let test_is_flaky = 1
+  let g:test_is_flaky = 1
 
   call assert_equal("running", term_getstatus(a:buf))
 

src/testdir/test_autocmd.vim

@@ -1869,7 +1869,7 @@ func Test_Changed_FirstTime()
   CheckFeature terminal
   CheckNotGui
   " Starting a terminal to run Vim is always considered flaky.
-  let test_is_flaky = 1
+  let g:test_is_flaky = 1
 
   " Prepare file for TextChanged event.
   call writefile([''], 'Xchanged.txt')

src/version.c

@@ -738,6 +738,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    402,
 /**/
     401,
 /**/