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/util/process.c

@@ -5,8 +5,8 @@
 #include "log.h"
 
 enum sc_process_result
-sc_process_execute(const char *const argv[], sc_pid *pid) {
-    return sc_process_execute_p(argv, pid, NULL, NULL, NULL);
+sc_process_execute(const char *const argv[], sc_pid *pid, unsigned flags) {
+    return sc_process_execute_p(argv, pid, flags, NULL, NULL, NULL);
 }
 
 ssize_t