Remove vkGetInstanceProcAddr from exported symbols on Android

Android only allows access to the ICD's functions, through the Vulkan
Loader interface functions.

This was causing direct access to vkGetPhysicalDeviceSurfaceFormatsKHR,
while Android's libvulkan must override it to provide an implementation
based on AHardwareBuffer, which affects things like wide-gamut support.

Bug: b/182576189
Bug: b/148822450
Change-Id: I64fd5a601f92beca186696d2cd09eee1a09b8ce9
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/53608
Reviewed-by: Jason Macnak <natsu@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Tested-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/Vulkan/android_vk_swiftshader.lds b/src/Vulkan/android_vk_swiftshader.lds
index 7ee098c..be404d9 100644
--- a/src/Vulkan/android_vk_swiftshader.lds
+++ b/src/Vulkan/android_vk_swiftshader.lds
@@ -1,8 +1,6 @@
 # For Android, we must not export anything other than loader-related API
 {
 global:
-	vkGetInstanceProcAddr;
-
 	# Loader-ICD interface functions
 	vk_icdGetInstanceProcAddr;
 	vk_icdNegotiateLoaderICDInterfaceVersion;