Remove separate_platform_variant entries.

This no longer does anything.

Bug: 161456198
Test: build
Change-Id: If7ca08cc1d7a829c637e1ea8254eed6361be0490
diff --git a/dumpstate/aidl/Android.bp b/dumpstate/aidl/Android.bp
index e18eade..22d836b 100644
--- a/dumpstate/aidl/Android.bp
+++ b/dumpstate/aidl/Android.bp
@@ -34,7 +34,6 @@
             enabled: false,
         },
         ndk: {
-            separate_platform_variant: false,
             vndk: {
                 enabled: true,
             },
diff --git a/health/aidl/Android.bp b/health/aidl/Android.bp
index 6e2f1d4..22bb4fa 100644
--- a/health/aidl/Android.bp
+++ b/health/aidl/Android.bp
@@ -37,7 +37,6 @@
             sdk_version: "module_current",
         },
         ndk: {
-            separate_platform_variant: false,
             vndk: {
                 enabled: true,
             },
diff --git a/ir/aidl/Android.bp b/ir/aidl/Android.bp
index 8741157..6dacb85 100644
--- a/ir/aidl/Android.bp
+++ b/ir/aidl/Android.bp
@@ -25,7 +25,6 @@
             sdk_version: "module_current",
         },
         ndk: {
-            separate_platform_variant: false,
             vndk: {
                 // TODO(b/206116595) enable this
                 enabled: false,