This allows the refactoring which will happen after default_applicable_licenses is renamed to default_package_metadata. The current behavior is intended to prevent
`applicable_licenses` from being set on a `license` rule. The required behavior is that we don't set `applicable_licenses` on any of the metadata rules.

Future changes might have to take into account the ability to set the license for a tool rule within `rules_package`.

For background, see https://docs.google.com/document/d/1uyJjkKbE8kV8EinakaR9q-Un25zCukhoH_dRBkWHSKQ/edit#heading=h.izpa22p82m6c

Closes #16596.

PiperOrigin-RevId: 485457037
Change-Id: Ifb105f646ae0c291a6841b3ddb84ed536e9d71e3

* Rename default_applicable_licenses to default_package_metadata.

Leave default_applicable_licenses as an alias.
Don't allow both to be set.

Step 1 of https://docs.google.com/document/d/1uyJjkKbE8kV8EinakaR9q-Un25zCukhoH_dRBkWHSKQ/edit#

PiperOrigin-RevId: 485705150
Change-Id: I5e0012e37e5bca55ed43f83dd9f26a26f78b543d

* Improve the check for being a package metadata rule

This allows the refactoring which will happen after default_applicable_licenses is renamed to default_package_metadata. The current behavior is intended to prevent
`applicable_licenses` from being set on a `license` rule. The required behavior is that we don't set `applicable_licenses` on any of the metadata rules.

Future changes might have to take into account the ability to set the license for a tool rule within `rules_package`.

For background, see https://docs.google.com/document/d/1uyJjkKbE8kV8EinakaR9q-Un25zCukhoH_dRBkWHSKQ/edit#heading=h.izpa22p82m6c

Closes #16596.

PiperOrigin-RevId: 485457037
Change-Id: Ifb105f646ae0c291a6841b3ddb84ed536e9d71e3

* Make constraint_setting / constraint_value non_configurable.

The concept of allowing what is fundamentally a constant to vary by target we are building for is too much to reason about, let along get the code correct.

PiperOrigin-RevId: 483748098
Change-Id: I966b7d21ad8d38de9867c870a0669e2123063809

This allows the refactoring which will happen after default_applicable_licenses is renamed to default_package_metadata. The current behavior is intended to prevent
`applicable_licenses` from being set on a `license` rule. The required behavior is that we don't set `applicable_licenses` on any of the metadata rules.

Future changes might have to take into account the ability to set the license for a tool rule within `rules_package`.

For background, see https://docs.google.com/document/d/1uyJjkKbE8kV8EinakaR9q-Un25zCukhoH_dRBkWHSKQ/edit#heading=h.izpa22p82m6c

Closes bazelbuild#16596.

PiperOrigin-RevId: 485457037
Change-Id: Ifb105f646ae0c291a6841b3ddb84ed536e9d71e3