Remove ld.config.txt from prebuilts build rule

Starting from the P VNDK snapshot, the linker config file will be
built and installed from the source tree at the time the VNDK
snapshot is installed to the system.img (of Q+), rather than
installing the prebuilt from /prebuilts/vndk/v{VER}. The installed
linker config file is used for both system and vendor processes,
thus should be built from the most up-to-date ld.config.txt
template in the source tree of the system partition.

Test: python gen_buildfiles.py 28 -vv
Test: m -j vndk_v28_arm64; check /system/etc/ld.config.28.txt
Bug: 74658756
Merged-In: I86034e6bbbab6a096814389332c26920ef7d40fc
Change-Id: I86034e6bbbab6a096814389332c26920ef7d40fc
(cherry picked from commit e020f7131e)

vndk/snapshot/gen_buildfiles.py

@@ -119,6 +119,12 @@ class GenBuildFile(object):
             self._vndk_version))
         etc_buildrules = []
         for prebuilt in self.ETC_MODULES:
+            # Starting from P (VNDK version >= 28), ld.config.VER.txt is not
+            # installed as a prebuilt but is built and installed from the
+            # source tree at the time the VNDK snapshot is installed to the
+            # system.img.
+            if prebuilt == 'ld.config.txt' and self._vndk_version >= 28:
+                continue
             etc_buildrules.append(self._gen_etc_prebuilt(prebuilt))
 
         with open(self._mkfile, 'w') as mkfile: