Update ray tracing samples to use VK_KHR_ray_tracing (#753)

* Started updating ray tracing samples to KHR extension

* Updated GLSL shaders to use GL_EXT_ray_tracing

* Code cleanup, naming

* Fix include directories to use Vulkan headers from repository instead of NDK for the Android build

* Added new Android function pointers

* Renamed basic ray tracing sample

Added android build files

* Remove unused batch file

* Replaced remaining NV identifiers

* Updating ray tracing shadow sample to KHR extension

* Updated shaders to use KHR instead of NV extension

Fixed shader bindings

* Updating ray tracing reflections sample to KHR extension

* Renamed ray tracing reflections sample

* Renamed ray tracing shadows sample

Added android build files

* Removed no-longer used batch files for shader generation

* Proper alignment for the shader binding table

* Updated readme

* Reworked shader group setup

* Cleanup

* Reworked shader group setup

* Reworked shader group setup

* Code cleanup

android/examples/raytracingbasic/build.gradle

@@ -0,0 +1,60 @@
+apply plugin: 'com.android.application'
+apply from: '../gradle/outputfilename.gradle'
+
+android {
+    compileSdkVersion 26
+    defaultConfig {
+        applicationId "de.saschawillems.vulkanRaytracingbasic"
+        minSdkVersion 19
+        targetSdkVersion 26
+        versionCode 1
+        versionName "1.0"
+        ndk {
+            abiFilters "armeabi-v7a"
+        }
+        externalNativeBuild {
+            cmake {
+                cppFlags "-std=c++14"
+                arguments "-DANDROID_STL=c++_shared", '-DANDROID_TOOLCHAIN=clang'
+            }
+        }
+    }
+    sourceSets {
+        main.assets.srcDirs = ['assets']
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+    externalNativeBuild {
+        cmake {
+            path "CMakeLists.txt"
+        }
+    }
+}
+
+task copyTask {
+    copy {
+        from '../../common/res/drawable'
+        into "src/main/res/drawable"
+        include 'icon.png'
+    }
+
+    copy {
+        from '../../../data/shaders/glsl/base'
+        into 'assets/shaders/glsl/base'
+        include '*.spv'
+    }
+
+    copy {
+       from '../../../data/shaders/glsl/raytracingbasic'
+       into 'assets/shaders/glsl/raytracingbasic'
+       include '*.*'
+    }
+
+
+}
+
+preBuild.dependsOn copyTask