Using CentOS7 templates on Azure could result in lack of LVM, swap and non auto-extendable partitions. Some other templates have such feature, but not all of them. In case you assigned bigger disk in Azure portal you need still to do few things. First delete /dev/sda2 partition:

fdisk /dev/sda
d
2
w

Then reboot to apply.

yum install cloud-utils-growpart -y
growpart /dev/sda 1
xfs_growfs /dev/sda1