releasetools: Drop the support for BBOTA v1 and v2.

BBOTA v1 and v2 (introduced in L and L MR1 respectively) don't support
resumable OTA. We shouldn't generate packages using v1/v2 at the risk of
bricking devices.

BBOTA v3 (since M) and v4 (since N) both support resumable OTAs. BBOTA
v4 additionally supports using FEC to possibly recover a corrupted
image.

Bug: 33694730
Test: Generate full and incremental OTAs w/ and w/o the CL. They should
      give identical packages (in v4).
Change-Id: Ib89d9cd63ba08e8e9aa4131bed18876b89d244c0
diff --git a/core/Makefile b/core/Makefile
index 5a74763..3a570c7 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -2053,7 +2053,7 @@
 	$(hide) echo 'mkbootimg_args=$(BOARD_MKBOOTIMG_ARGS)' >> $(zip_root)/META/misc_info.txt
 	$(hide) echo 'mkbootimg_version_args=$(INTERNAL_MKBOOTIMG_VERSION_ARGS)' >> $(zip_root)/META/misc_info.txt
 	$(hide) echo "multistage_support=1" >> $(zip_root)/META/misc_info.txt
-	$(hide) echo "blockimgdiff_versions=1,2,3,4" >> $(zip_root)/META/misc_info.txt
+	$(hide) echo "blockimgdiff_versions=3,4" >> $(zip_root)/META/misc_info.txt
 ifneq ($(OEM_THUMBPRINT_PROPERTIES),)
 	# OTA scripts are only interested in fingerprint related properties
 	$(hide) echo "oem_fingerprint_properties=$(OEM_THUMBPRINT_PROPERTIES)" >> $(zip_root)/META/misc_info.txt