default to v102 everywhere, instead of vt100, to synchronize with agetty

src/shared/util.c

@@ -4352,7 +4352,7 @@ bool tty_is_vc_resolve(const char *tty) {
 const char *default_term_for_tty(const char *tty) {
         assert(tty);
 
-        return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt100";
+        return tty_is_vc_resolve(tty) ? "TERM=linux" : "TERM=vt102";
 }
 
 bool dirent_is_file(const struct dirent *de) {

units/serial-getty@.service.m4

@@ -35,7 +35,7 @@ Before=getty.target
 IgnoreOnIsolate=yes
 
 [Service]
-Environment=TERM=vt100
+Environment=TERM=vt102
 ExecStart=-/sbin/agetty -s %I 115200,38400,9600
 Restart=always
 RestartSec=0