Skip invalid end2end test for ES2

Previously, the incomplete framebuffer depth stencil attachment
test would run on ES2 if GL_OES_packed_depth_stencil were present.
This is insufficient since it uses the GL_DEPTH_STENCIL_ATTACHMENT
enum, which is not introduced in any extension prior to ES3. The
test has been disabled on ES2, regardless of extensions.

Bug: angleproject:4454
Test: angle_end2end_tests --gtest_filter=StateChangeTest.FramebufferIncompleteDepthStencilAttachment/*
Change-Id: Ic5a6a521e35b49c5d723b33f588fa608264d6390
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2090783
Commit-Queue: Mohan Maiya <m.maiya@samsung.com>
Reviewed-by: Jamie Madill <jmadill@chromium.org>

src/tests/gl_tests/StateChangeTest.cpp

@@ -251,11 +251,8 @@ TEST_P(StateChangeTest, FramebufferIncompleteStencilAttachment)
 }
 
 // Test that Framebuffer completeness caching works when depth-stencil attachments change.
-TEST_P(StateChangeTest, FramebufferIncompleteDepthStencilAttachment)
+TEST_P(StateChangeTestES3, FramebufferIncompleteDepthStencilAttachment)
 {
-    ANGLE_SKIP_TEST_IF(getClientMajorVersion() < 3 &&
-                       !IsGLExtensionEnabled("GL_OES_packed_depth_stencil"));
-
     glBindFramebuffer(GL_FRAMEBUFFER, mFramebuffer);
     glBindTexture(GL_TEXTURE_2D, mTextures[0]);
     glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 16, 16, 0, GL_RGBA, GL_UNSIGNED_BYTE, nullptr);