Install VNDK libs in /system instead of /vendor

If BOARD_VNDK_VERSION is set, and a module is set to
`vendor_available: true` it is installed in /system and /vendor.

However, if the module is a VNDK library, it must be
installed at `/system/${LIB}/vndk` instead of /vendor/${LIB}.
For those modules, need following to set.

vendor_available: true,
vndk: {
    enabled: true,
    support_system_process: true,
},

`support_system_process` is optional to define.
If it is defined to true, the module is regarded as vndk-sp.

link-type check for VNDK modules is added to make sure that VNDK
modules only link to other VNDK shared libraries or LL-NDKs.

move the ABI checks to VNDK from all of vendor_available.

Bug: 38304436
Test: attempt to compile with BOARD_VNDK_VERSION:=current
Test: Use `vendor_available_vndk: true` for VNDK modules and compile
      with BOARD_VNDK_VERSION:=current
Change-Id: I409268e0b7f05a9d01697bf9f9f4726b5aac631f

cc/sabi.go

@@ -72,7 +72,7 @@ func (sabimod *sabi) flags(ctx ModuleContext, flags Flags) Flags {
 
 func sabiDepsMutator(mctx android.TopDownMutatorContext) {
 	if c, ok := mctx.Module().(*Module); ok &&
-		(Bool(c.Properties.Vendor_available) || (inList(c.Name(), config.LLndkLibraries())) ||
+		(c.isVndk() || inList(c.Name(), config.LLndkLibraries()) ||
 			(c.sabi != nil && c.sabi.Properties.CreateSAbiDumps)) {
 		mctx.VisitDirectDeps(func(m blueprint.Module) {
 			tag := mctx.OtherModuleDependencyTag(m)