scripts: upload_prebuilts: Handle version prefixes other than "chroot-"

Previously, upload_prebuilts assumed that the version prefix was "chroot-",
and chopped off the first 7 characters of the prefix+version string to
get the version alone. This updates the code to be a bit more robust,
instead looking for the expected format of the version and stripping
the prefix that precedes it.

BUG=b:289990183
TEST=./run_tests scripts/upload_prebuilts_unittest.py

Change-Id: Id36dd69c0e7529885151f26f41d86b5ce573de5b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/4669938
Commit-Queue: Bob Haarman <inglorion@chromium.org>
Tested-by: Bob Haarman <inglorion@chromium.org>
Reviewed-by: Lizzy Presland <zland@google.com>
diff --git a/scripts/upload_prebuilts_unittest.py b/scripts/upload_prebuilts_unittest.py
index 47dbaf8..09bb2b1 100644
--- a/scripts/upload_prebuilts_unittest.py
+++ b/scripts/upload_prebuilts_unittest.py
@@ -667,6 +667,8 @@
 class TestSdk(cros_test_lib.MockTestCase):
     """Test logic related to uploading SDK binaries"""
 
+    VERSION_PREFIX = "cros-"
+
     def setUp(self):
         self.PatchObject(
             prebuilt,
@@ -706,7 +708,7 @@
             False,
             "x86-foo",
             [],
-            "chroot-1234",
+            f"{self.VERSION_PREFIX}-1234.08.01.5678",
             report={},
         )
 
@@ -719,7 +721,7 @@
     ):
         """Make sure we can upload just an SDK tarball"""
         tar = "sdk.tar.xz"
-        ver = "1234"
+        ver = "1234.08.01.5678"
         vtar = "cros-sdk-%s.tar.xz" % ver
 
         upload_calls = [
@@ -805,6 +807,12 @@
         )
 
 
+class TestSdkBuildToolchain(TestSdk):
+    """Like TestSdk, but uses a different version prefix."""
+
+    VERSION_PREFIX = "build_toolchain-"
+
+
 @pytest.mark.parametrize(
     "extra_args,expected_sync",
     [