keymaps/Japanese: Japanese keymap do not use Alt Gr key

Set modifier keys as following:
- Right Cmd -> Right Alt
- Right Opt -> Right Win

Change-Id: I61a193a7690fca8486ecd2c17eb672d24d69e241
Reviewed-on: https://review.haiku-os.org/c/haiku/+/6471
Reviewed-by: Adrien Destugues <pulkomandy@pulkomandy.tk>
Tested-by: Commit checker robot <no-reply+buildbot@haiku-os.org>

src/data/keymaps/Japanese.keymap

@@ -37,11 +37,11 @@ NumLock = 0x22
 LShift = 0x4b
 RShift = 0x56
 LCommand = 0x5d
-RCommand = 0x00
+RCommand = 0x5f
 LControl = 0x5c
 RControl = 0x60
 LOption = 0x66
-ROption = 0x5f
+ROption = 0x67
 Menu = 0x68
 #
 # Lock settings