Create default PRODUCT_INCLUDE_TAGS in product_config

In the current setup in partner branch, we
1. Add blueprint_package_includes to prebuilts/module_sdk/*
2. Add the correct PRODUCT_INCLUDE_TAGS to partner_modules

This means in those setups,none of the prebuilts are visible to aosp products since
they they do not inherit partner_module makefiles.
```
e.g.
prebuilts/module_sdk/art/current/Android.bp
prebuilts/module_sdk/art/<go_specific>/current/Android.bp

// aosp_arm cannot find either

```

To solve this, this CL creates a default inclusion tag for all products
that do not set any PRODUCT_INCLUDE_TAGS explicitly.
In the previous example, Soong analysis of aosp_* will use
prebuilts/module_sdk/art/current/Android.bp. This should be a no-op for
aosp and internal branches since none of the Android.bp files today contains
blueprint_package_includes

Test: m nothing for aosp_arm in the test branch of b/278604467#comment20
Test: m nothing for partner product that uses big android sdk
Test: m nothing for partner product that uses go sdk

Bug: 278604467
Change-Id: I322b52c34ed339989207609dd0fd23c27ed1f697