[gobject] Fix G_DEFINE_BOXED_TYPE compilation with C++
[gobject] Fix G_DEFINE_BOXED_TYPE compilation with C++

gale320/glib,djdeath/glib,darren-clark/android_platform_external_bluetooth_glib,pstglia/external-bluetooth-glib,johne53/MB3Glib,pstglia/platform-external-bluetooth-glib,tamaskenez/glib,justinkb/aosp-bluez.glib,cosimoc/glib,MathieuDuponchelle/glib,antono/glib,bluez-android/glib,cosimoc/glib,endlessm/glib,darren-clark/android_platform_external_bluetooth_glib,MathieuDuponchelle/glib,iConsole/Console-OS_external_bluetooth_glib,lukasz-skalski/glib,pstglia/external-bluetooth-glib,tchakabam/glib,pstglia/external-bluetooth-glib,tamaskenez/glib,ieei/glib,djdeath/glib,01org/android-bluez-glib,justinkb/aosp-bluez.glib,Distrotech/glib,antono/glib,krichter722/glib,antono/glib,pstglia/platform-external-bluetooth-glib,ieei/glib,mzabaluev/glib,pstglia/platform-external-bluetooth-glib,endlessm/glib,darren-clark/android_platform_external_bluetooth_glib,01org/android-bluez-glib,cention-sany/glib,lukasz-skalski/glib,krichter722/glib,MathieuDuponchelle/glib,01org/android-bluez-glib,endlessm/glib,pstglia/external-bluetooth-glib,bluez-android/glib,djdeath/glib,antono/glib,cention-sany/glib,bluez-android/glib,pstglia/platform-external-bluetooth-glib,mzabaluev/glib,lukasz-skalski/glib,lukasz-skalski/glib,Distrotech/glib,tchakabam/glib,MathieuDuponchelle/glib,lukasz-skalski/glib,cention-sany/glib,endlessm/glib,01org/android-bluez-glib,bluez-android/glib,cosimoc/glib,justinkb/aosp-bluez.glib,krichter722/glib,johne53/MB3Glib,krichter722/glib,iConsole/Console-OS_external_bluetooth_glib,ieei/glib,krichter722/glib,djdeath/glib,cention-sany/glib,darren-clark/android_platform_external_bluetooth_glib,iConsole/Console-OS_external_bluetooth_glib,djdeath/glib,johne53/MB3Glib,Distrotech/glib,mzabaluev/glib,johne53/MB3Glib,mzabaluev/glib,justinkb/aosp-bluez.glib,ieei/glib,01org/android-bluez-glib,ieei/glib,cention-sany/glib,tchakabam/glib,Distrotech/glib,gale320/glib,johne53/MB3Glib,mzabaluev/glib,justinkb/aosp-bluez.glib,cosimoc/glib,tchakabam/glib,iConsole/Console-OS_external_bluetooth_glib,MathieuDuponchelle/glib,Distrotech/glib,gale320/glib,bluez-android/glib,tamaskenez/glib,gale320/glib,johne53/MB3Glib,darren-clark/android_platform_external_bluetooth_glib,tchakabam/glib,gale320/glib,tamaskenez/glib,pstglia/external-bluetooth-glib,tamaskenez/glib,endlessm/glib,pstglia/platform-external-bluetooth-glib,iConsole/Console-OS_external_bluetooth_glib,cosimoc/glib