If you have installed your BSP into /opt (1.2 Unpack i.MX Android Release Package), then you probably forgot to unpack r10.2.tar.gz inside /opt/imx-android-r10.2/code/ (cd /opt/imx-android-r10.2/code/; sudo tar -xzf r10.2.tar.gz).
However, even if you have the file 'default.xml' from your BSP available, copying it on top of the default 'default.xml' file inside Android tree is not recommended, as google moved Android's repositories to new servers and the links will differ. I would suggest you to compare the files mannually or download a newr Android BSP, which is already adpated to the new Android servers.