Don't merge apex variations with different UsePlatformApis

Merging apex variations with different UsePlatformApis results in
the presence of an extra apex with UsePlatformApis false changing
the behavior of an existing apex -> module dependency with
UsePlatformApis true, which can't be supported with incremental
analysis.  Don't merge apex variations with different UsePlatformApis
values, and add a _p suffix to the UsePlatformApis variation so they
can coexist.

Test: Test_mergeApexVariations
Bug: 372543712
Change-Id: I0e857a646a0449f87e4de6e6306ec921bc46fac1
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 78f2463..d6cb79a 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -1249,12 +1249,12 @@
 
 	// Ensure that we are using non-stub variants of mylib2 and libfoo.shared_from_rust (because
 	// of the platform_apis: true)
-	mylibLdFlags := ctx.ModuleForTests("mylib", "android_arm64_armv8-a_shared_apex10000").Rule("ld").Args["libFlags"]
+	mylibLdFlags := ctx.ModuleForTests("mylib", "android_arm64_armv8-a_shared_apex10000_p").Rule("ld").Args["libFlags"]
 	ensureNotContains(t, mylibLdFlags, "mylib2/android_arm64_armv8-a_shared_current/mylib2.so")
 	ensureContains(t, mylibLdFlags, "mylib2/android_arm64_armv8-a_shared/mylib2.so")
 	ensureNotContains(t, mylibLdFlags, "libmylib2_rust/android_arm64_armv8-a_shared_current/unstripped/libmylib2_rust.so")
 	ensureContains(t, mylibLdFlags, "libmylib2_rust/android_arm64_armv8-a_shared/unstripped/libmylib2_rust.so")
-	rustDeps := ctx.ModuleForTests("foo.rust", "android_arm64_armv8-a_apex10000").Rule("rustc").Args["linkFlags"]
+	rustDeps := ctx.ModuleForTests("foo.rust", "android_arm64_armv8-a_apex10000_p").Rule("rustc").Args["linkFlags"]
 	ensureNotContains(t, rustDeps, "libfoo.shared_from_rust/android_arm64_armv8-a_shared_current/libfoo.shared_from_rust.so")
 	ensureContains(t, rustDeps, "libfoo.shared_from_rust/android_arm64_armv8-a_shared/libfoo.shared_from_rust.so")
 	ensureNotContains(t, rustDeps, "libmylib_rust.shared_from_rust/android_arm64_armv8-a_shared_current/unstripped/libmylib_rust.shared_from_rust.so")