Drop exported_bootclasspath_fragments from prebuilt com.android.xxx
APEXes.

This avoids ambiguity when deciding which prebuilt APEX to use for
deapexing in platform builds where there are other prebuilts than
these.

This is a workaround - a proper solution for this requires introducing
a product variable to specify which APEXes to use, but that requires a
lot of engineering effort (b/192006406).

exported_bootclasspath_fragments is only required to use these prebuilt
APEXes in system images, and currently there are no plans to use these
there - they are only used in chroot testing on the thin manifest
master-art branch.

Test: m droid SOONG_CONFIG_art_module_source_build=false
  on internal master
Test: art/build/build-art-module.sh
  on master-art
Test: art/tools/buildbot-build.sh --target
  on master-art
Bug: 192006406
Bug: 202192894
Change-Id: I6ec7047e3fae90b19a6216b1022fe0faac2b1222
diff --git a/mainline/conscrypt/apex/Android.bp b/mainline/conscrypt/apex/Android.bp
index 67e2961..5fe1151 100644
--- a/mainline/conscrypt/apex/Android.bp
+++ b/mainline/conscrypt/apex/Android.bp
@@ -35,11 +35,4 @@
         },
     },
     filename: "com.android.conscrypt.apex",
-
-    // Make fragment related files from the apex file available for use by the
-    // build when using prebuilts, e.g. for running the boot jars package check
-    // and hidden API flag validation among other uses.
-    exported_bootclasspath_fragments: [
-        "com.android.conscrypt-bootclasspath-fragment",
-    ],
 }
diff --git a/mainline/i18n/apex/Android.bp b/mainline/i18n/apex/Android.bp
index f7cbfe1..497add7 100644
--- a/mainline/i18n/apex/Android.bp
+++ b/mainline/i18n/apex/Android.bp
@@ -40,11 +40,4 @@
         },
     },
     filename: "com.android.i18n.apex",
-
-    // Make fragment related files from the apex file available for use by the
-    // build when using prebuilts, e.g. for running the boot jars package check
-    // and hidden API flag validation among other uses.
-    exported_bootclasspath_fragments: [
-        "i18n-bootclasspath-fragment",
-    ],
 }