Fix apex_available

Checking apex_available was missing some corner cases.
For example, the deps of share deps of cc_library modules are missed
while those from cc_library_shared are correctly tracked.

This was due to..

* calling DepIsInSameApex in WalkDeps: both work fine separately, but
when they are used together, it fails to work. It's due to how WalkDeps
works. (We might fix this bug too risky since it is used very widely)
* incorrect receiver for DepIsInSameApex in apex_deps mutator: receiver
is supposed to be parent, but child was used before. Interestingly lots
of deps are within the same group of module types(cc to cc, java to
java), it has worked. (note that receiver's DepIsInSameApex
implementation can be different).

This change fixes them by..

* walkPayloadDeps is now relying on ApexVariation, which is calculated
correctly by TopDown apex_deps mutator.
* use correct receiver for DepIsInSameApex in apex_deps mutator, which
requires for java.SdkLibrary to override the method and for
java.Library/Import to use passed dep instead of receiver to check its
membership of sdk.

Bug: 151071238
Test: build/boot
Change-Id: I0569ef4bb8e79635e4d97a89f421a8d8b7d26456