Expose flags for process execution

Let the caller decide if stdout and stderr must be inherited on process
creation, i.e. if stdout and stderr of the child process should be
printed in the scrcpy console.

This allows to get output and errors for specific adb commands depending
on the context.

PR #2827 <https://github.com/Genymobile/scrcpy/pull/2827>

app/src/adb.c

@@ -181,7 +181,7 @@ adb_execute_p(const char *serial, const char *const adb_cmd[], size_t len,
 
     sc_pid pid;
     enum sc_process_result r =
-        sc_process_execute_p(argv, &pid, NULL, pout, NULL);
+        sc_process_execute_p(argv, &pid, 0, NULL, pout, NULL);
     if (r != SC_PROCESS_SUCCESS) {
         show_adb_err_msg(r, argv);
         pid = SC_PROCESS_NONE;