This change fixed the problem that boot_image modules when installed to
an APEX get incorrect names like signed.img. The filename now is
"<modulename>.img" and can be overridden via the new `stem` property.
Bug: 178978059
Test: m
Change-Id: I1b25db04a4a2d888371b174c42f91a0cea87b877
The new module type is to build the boot partition images. Boot
partition image consists of kernel, ramdisk, dtb, etc. which are
processed by the mkbootimg tool. There are two flavors of boot
partition: boot and vendor_boot. The choice is configured via the
'vendor_boot' property. Currently, only `vendor_boot: true` case is
supported.
But: 178978059
Test: m cf_bootimg-5.10
Change-Id: Iee689d9d666e8e6e5af7db02a76dd39d1e4d0e3a
