With the changes to support APF v13 in the `ng_package` rule, we have
removed the ambiguous `entry_point` attribute. The attribute suggested
that it would be used for determining the primary entry-point input
file. This was not the case as the flat module output file is consulted
for bundling et at. The attribute has been renamed to match its
purposed (renamed to `primary_bundle_name`).
We no longer need to set that attribute because the primary bundle
name is (1) not of relevance for consumers and (2) the rule already
infers the bundle name properly from the Bazel package.
PR Close#43431
