Mark platform build as deprecated on gradle

Test: ./gradlew buildProjectFull
Bug: 33298315
Change-Id: I265ab8468a75dbe23749259a36f9aba06abbc8ed

library/rules.gradle

@@ -16,8 +16,8 @@ android {
     flavorDimensions 'compat'
 
     productFlavors {
-        // Platform version that will not include the compatibility libraries
-        platform {
+        // DEPRECATED: Platform version that will not include the compatibility libraries
+        platformDeprecated {
             dimension 'compat'
             minSdkVersion 23
         }
@@ -37,7 +37,7 @@ android {
             res.srcDirs = ['main/res']
         }
 
-        platform {
+        platformDeprecated {
             java.srcDirs = ['platform/src']
             res.srcDirs = ['platform/res']
         }
@@ -66,7 +66,7 @@ dependencies {
     //          deps = ['project-name': 'com.example.group:project-name:1.0.0']
     //      }
     //
-    platformCompile deps['support-annotations']
+    platformDeprecatedCompile deps['support-annotations']
 
     gingerbreadCompatCompile deps['support-appcompat-v7']
     gingerbreadCompatCompile deps['support-recyclerview-v7']

library/self.gradle

@@ -22,7 +22,7 @@ android.sourceSets {
         }
     }
 
-    androidTestPlatform {
+    androidTestPlatformDeprecated {
         java.srcDirs = ['platform/test/src']
     }