Reactivate "turn device screen on" feature

This reverts commit 8c8649cfcd.

I cannot reproduce the issue with Ctrl+Shift+o on any device, so in
practice it works, it's too bad to remove the feature for a random bug
on some Android versions on some devices.

README.md

@@ -576,6 +576,7 @@ Also see [issue #14].
  | Click on `POWER`                            | `Ctrl`+`p`                    | `Cmd`+`p`
  | Power on                                    | _Right-click²_                | _Right-click²_
  | Turn device screen off (keep mirroring)     | `Ctrl`+`o`                    | `Cmd`+`o`
+ | Turn device screen on                       | `Ctrl`+`Shift`+`o`            | `Cmd`+`Shift`+`o`
  | Rotate device screen                        | `Ctrl`+`r`                    | `Cmd`+`r`
  | Expand notification panel                   | `Ctrl`+`n`                    | `Cmd`+`n`
  | Collapse notification panel                 | `Ctrl`+`Shift`+`n`            | `Cmd`+`Shift`+`n`

app/scrcpy.1

@@ -259,6 +259,10 @@ Turn screen on
 .B Ctrl+o
 Turn device screen off (keep mirroring)
 
+.TP
+.B Ctrl+Shift+o
+Turn device screen on
+
 .TP
 .B Ctrl+r
 Rotate device screen

app/src/cli.c

@@ -231,6 +231,9 @@ scrcpy_print_usage(const char *arg0) {
         "    " CTRL_OR_CMD "+o\n"
         "        Turn device screen off (keep mirroring)\n"
         "\n"
+        "    " CTRL_OR_CMD "+Shift+o\n"
+        "        Turn device screen on\n"
+        "\n"
         "    " CTRL_OR_CMD "+r\n"
         "        Rotate device screen\n"
         "\n"

app/src/input_manager.c

@@ -321,8 +321,11 @@ input_manager_process_key(struct input_manager *im,
                 }
                 return;
             case SDLK_o:
-                if (control && cmd && !shift && down) {
-                    set_screen_power_mode(controller, SCREEN_POWER_MODE_OFF);
+                if (control && cmd && down) {
+                    enum screen_power_mode mode = shift
+                                                ? SCREEN_POWER_MODE_NORMAL
+                                                : SCREEN_POWER_MODE_OFF;
+                    set_screen_power_mode(controller, mode);
                 }
                 return;
             case SDLK_DOWN: